This is a beginner level project for anyone looking to start in web3 space.

Writing your first Hello World contract in Solidity

In this section, we will setup the environment which will act as the basis for writing the smart contract code. We will create accounts on Alchemy, MetaMask and get some fake eth.

<p>Heya folks! I am <a href="https://twitter.com/fatimarizwan" target="_blank" rel="noopener noreferrer">Fama</a> and today I will be helping you write your first ever solidity contract. Not only this, there is much more fun stuff we will be doing during this project. So be excited and please bring your A game here.&nbsp;&nbsp;<br><br>We will cover some&nbsp;&nbsp;<br><br>1. Super cool tools that you need to interact with as a smart contract developer.&nbsp;&nbsp;<br>2. Writing your first ever solidity contract.&nbsp;&nbsp;<br>3. Shipping it to testnet and thennnn, interacting with it too. 🔥🔥&nbsp;&nbsp;<br>4. And understanding transactions on blockchain.</p><h2>Course Overview</h2><p></p><figure class="media"><div data-oembed-url="https://www.loom.com/share/a8686ce38843432e89dd95577569dad2?sharedAppSource=personal_library"><div class="se-component se-video-container __se__float-" contenteditable="false" style="width: 100%;"><figure style="width: 100%; height: 100%; padding-bottom: 100%; margin: 0px;"><iframe src="https://www.loom.com/embed/a8686ce38843432e89dd95577569dad2" data-percentage="100%,100%" data-size="100%,100%" data-align="" data-file-name="a8686ce38843432e89dd95577569dad2" data-file-size="0" data-origin="100%,100%" style="position: absolute; width: 100%; height: 100%; top: 0; left: 0;" data-index="0"></iframe></figure></div><div style="position: relative; padding-bottom: 100%; height: 0; "><br></div></div></figure><p></p><p>Please install VScode and node on your machine. Install&nbsp;<a href="https://nodejs.org/en/" target="_blank" rel="noopener noreferrer"><u>node from here</u></a>. Download&nbsp;<a href="https://code.visualstudio.com/" target="_blank" rel="noopener noreferrer"><u>VScode from here.</u></a></p><p>If you complete this course with me today, you will be getting a special NFT, a utility token, which will unlock many more opportunities for you on the Metaschool platform. Here is how the NFT looks like.</p><div class="se-component se-image-container __se__float- __se__float-none" contenteditable="false"><figure style="margin: 0px;"><img src="https://lh3.googleusercontent.com/XA90aG5m4td1tcxoknDWavsFAFTULftVrzyhnLu8oM5AwEXm93ZChVq5D1h9gqkhMKPKHBkuOzyeA7jMjzogVRngAshjOaLsQo5lsn2U8ZtLt-jUMfZ0gzY5K2B7NdIM8oju6Lhw" data-origin="," alt="" data-proportion="true" data-align="none" data-file-name="XA90aG5m4td1tcxoknDWavsFAFTULftVrzyhnLu8oM5AwEXm93ZChVq5D1h9gqkhMKPKHBkuOzyeA7jMjzogVRngAshjOaLsQo5lsn2U8ZtLt-jUMfZ0gzY5K2B7NdIM8oju6Lhw" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" data-size="," data-percentage="auto,auto" style="" data-index="0"></figure></div><p><br></p><p>Now before we move forward, let’s set some house rules first.&nbsp;&nbsp;&nbsp;<br><br>1. Pleaseeeee do your quick assignments properly.&nbsp;&nbsp;&nbsp;<br>2. Join&nbsp;<a href="https://discord.gg/vbVMUwXWgc" target="_blank" rel="noopener noreferrer"><u>our discord server</u></a> and ask all relevant questions there.&nbsp;&nbsp;&nbsp;<br>3. Stay happy and positive!</p><h2 style="margin-left:0px;">🛠 Contributing to this project!</h2><p style="margin-left:0px;">Good news! This is an open source project, you can find the tutorial markdown files <a href="https://github.com/0xmetaschool/Learning-Projects" target="_blank" rel="noopener noreferrer"><u>here</u></a> &amp; the code <a href="https://github.com/0xmetaschool/Hello-World-Smart-Contract" target="_blank" rel="noopener noreferrer"><u>here</u></a>. If you find an issues in the code or tutorial, please feel free to resolve it. We love love love contributions by our community and we give acknowledgement to contributors in our discord and github profile too.</p><p style="margin-left:0px;">Also, don’t forget to star ⭐️ our repository! we will be very thankful! ♥️</p>

﻿# What Are We Building Today?

gm everyone 🌈, I am [Fama](https://twitter.com/fatimarizwan) from Metaschool. I am very excited to bring the very new exciting course for developers just like you, who want to get started with the blockchain ecosystem!

So what are we building today? Today I will be helping you write your first ever solidity contract. Not only this, there is much more fun stuff we will be doing during this project. So be excited and please bring your A game here.

Why Solidity? Because many of the popular blockchains, [Ethereum](https://ethereum.org/en/), [Binance Smart Chain (BSC)](https://bscscan.com/), [Polygon](https://polygon.technology/) etc uses Solidity programming language to write smart contracts. Not only blockchains, but some of the biggest projects in web3 ecosystem, [Uniswap](https://uniswap.org/), [Compound](https://compound.finance/), [Yearn.finance](https://yearn.finance/) etc are in Solidity programming language.

Not only this, the Solidity docs have 580k visits per month and 2.15 pages per visit and almost 270k active Solidity developers per month. Yep! Solidity is the new hot thing in the developers community and Metaschool wants you to get ahead of 90% developers.

## Course overview

We will cover some

1. Super cool tools that you need to interact with as a smart contract developer.
2. Writing your first ever solidity contract.
3. Shipping it to testnet and thennnn, interacting with it too.
4. And understanding transactions on blockchain.

## Who exactly should take this course?

This course is for developers those have the basic programming knowledge. You are a developer who wants to transition or wants to learn about the web3 ecosystem.

## Prerequisites

- Node - Download [Node from here](https://nodejs.org/en/)
- VSCode - Download [VScode from here](https://code.visualstudio.com/)

## Proof of completion

If you complete this course with me today, you will be getting a special NFT, a utility token, which will unlock many more opportunities for you on the Metaschool platform. Here is how the NFT looks like.

![Untitled (1)](https://github.com/0xmetaschool/Learning-Projects/assets/129931419/39ec7f2b-da59-4a3c-b81f-90e3fe8c50c4)

Now before we move forward, let’s set some house rules first.

1. Pleaseeeee do your quick assignments properly.
2. Join [our discord server](https://discord.gg/vbVMUwXWgc) and ask all relevant questions there.
3. Stay happy and positive!

## 🛠 Contributing to this project!

Here’s the GREAT news for you! This is an open source project, you can find the tutorial markdown files [here](https://github.com/0xmetaschool/Learning-Projects/tree/main/Writing%20your%20first%20Hello%20World%20contract%20in%20Solidity) & the code [here](https://github.com/0xmetaschool/Hello-World-Smart-Contract). If you find an issues in the code or tutorial, please feel free to resolve it.

We, at Metaschool, love love love contributions by our community and we give acknowledgement to contributors in our discord and GitHub profile too.

Fun fact: All our projects are 100% open-source.

Also, don’t forget to star ⭐️ our repository! we will be very thankful! ♥️

Alright guys, no need to wait any longer, let's dive right into our awesome course! Let's do this! 🙌


https://raw.githubusercontent.com/0xmetaschool/Learning-Projects/main/Writing%20your%20first%20Hello%20World%20contract%20in%20Solidity/1.%20Setting%20up%20the%20environment/1.%20What%20Are%20We%20Building%20Today%3F.md

What Are We Building Today?

<p>Let’s get to setting up the environment first.&nbsp;&nbsp;<br><br>1. We will install and set up our Metamask account.&nbsp;&nbsp;<br>2. We will create an QuickNode app.</p><h4>Creating 🦊 MetaMask wallet&nbsp;</h4><p>Your Metamask wallet is your key to the web3 world. You can interact with the blockchain via a Metamask account. And of course, generally, it is your digital wallet to store, swap and buy cryptocurrencies, tokens, NFTs, and other amazing things in the web3 world.</p><p>Metamask has a mobile application and a Chrome browser extension too. I personally use Metamask on my Chrome browser extension because I do most of the work on my laptop.</p><p>Anyways, let’s go!</p><p>Here are the installation steps:</p><ul><li>Go to MetaMask.io</li><li>Click Download and Install the Chrome Extension.</li><li>Setup your secure password.&nbsp;</li><li>The next step is the most important one.</li><li>Secure your 12-word phrase properly, never share it with anyone. Write it somewhere because if you lose it, you will never have a way to recover your account. So be mindful of that.</li></ul><p>Congrats! your account is created and you must have received a public address. The public address will be in the pattern of:</p><p><em><u>Example: 0x37EA9984481459885141F571907992e7261E837C</u></em></p><p>You can use this public address to buy, trade, and store Ethereum based tokens, cryptos, NFTs and you can even use it to sign in to websites like OpenSea. But are you wondering if it is safe to share this cryptic long address?</p><p>Yes, it is completely safe. You can share this address publicly to accept, buy, trade or store Ethereum based crypto.</p><p>Here are the steps to turn on test networks</p><ol><li>Go to settings</li><li>Open Advanced</li><li>Scroll down to Show Test Networks</li><li>Turn on</li></ol><p></p><figure class="image"><div class="se-component se-image-container __se__float-none" contenteditable="false"><figure class="image" style="margin: 0px;"><img src="https://lh3.googleusercontent.com/J1aA9vZcf8gE3h9ypNI2nQ0-wRypnCCCwNBDHtc7C9qcyzlkbOmlb6IDUxxN1xIwQpfIwSPZrmXy-C5hS65lcFIKg5U0LZaXhGw_y2QxGurmhwZSHcJwK0gk5KCaUpu45pmz8jl2" data-origin="," alt="" data-proportion="true" data-align="none" data-file-name="J1aA9vZcf8gE3h9ypNI2nQ0-wRypnCCCwNBDHtc7C9qcyzlkbOmlb6IDUxxN1xIwQpfIwSPZrmXy-C5hS65lcFIKg5U0LZaXhGw_y2QxGurmhwZSHcJwK0gk5KCaUpu45pmz8jl2" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" data-size="," data-percentage="auto,auto" style="" data-index="0"></figure></div></figure><p></p><h4>&nbsp;</h4><h4 style="margin-left:0px;">Creating Quick Node ⛓ endpoint</h4><p>Now, we need to set up <a href="https://www.quicknode.com/?utm_source=partner&amp;utm_campaign=metaschool&amp;utm_content=metaschool-guides&amp;utm_medium=partner" target="_blank" rel="noopener noreferrer">QuickNode</a> with Ethereum testnet nodes, it’s gonna take like 5 mins.</p><p>QuickNode is a platform which helps you access the blockchain environment without going through the hassle of hosting your own node, saving time and resources. This platform lets you access blockchain nodes in a few clicks and you can scale the node performance according to your need thus creating an environment for you to scale your DApp.</p><ul><li>Sign in / Sign up to your<a href="https://www.quicknode.com/?utm_source=partner&amp;utm_campaign=metaschool&amp;utm_content=metaschool-guides&amp;utm_medium=partner" target="_blank" rel="noopener noreferrer">&nbsp;<strong><u>QuickNode</u></strong></a> account</li><li>Click on create an&nbsp;<a href="https://www.quicknode.com/?utm_source=partner&amp;utm_campaign=metaschool&amp;utm_content=metaschool-guides&amp;utm_medium=partner" target="_blank" rel="noopener noreferrer"><strong>QuickNode</strong></a> endpoint&nbsp;</li></ul><p></p><figure class="image"><div class="se-component se-image-container __se__float-none" contenteditable="false"><figure class="image" style="margin: 0px;"><img src="https://lh4.googleusercontent.com/nusZ81aRnb8ue5J6qJLN29NG-lQRe-oQcxoeHyplNrA2IpLKg3cBC2tXPE0XXg2JEI1ugLuCX-fSNFYdtJIctMYW9hLWo7jsQxun7aQU6w_0w1Hqb3Md6lMf1Q9bM57zAm0xKmNDzqCNghdNwYHetosBTnWTnmgCLKUarXGyuUs-EHxBKdN33yEVChkU-HQCo0RUCw" data-origin="," alt="" data-proportion="true" data-align="none" data-file-name="nusZ81aRnb8ue5J6qJLN29NG-lQRe-oQcxoeHyplNrA2IpLKg3cBC2tXPE0XXg2JEI1ugLuCX-fSNFYdtJIctMYW9hLWo7jsQxun7aQU6w_0w1Hqb3Md6lMf1Q9bM57zAm0xKmNDzqCNghdNwYHetosBTnWTnmgCLKUarXGyuUs-EHxBKdN33yEVChkU-HQCo0RUCw" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" data-size="," data-percentage="auto,auto" style="" data-index="1"></figure></div></figure><p></p><ul><li>Now select Ethereum as Network and Goerli as chain and continue</li><li>We don’t need any add-on so click&nbsp;<strong>create endpoint</strong> now</li></ul><p>Now once you create the endpoint you can start setting up our Metamask Wallet with QuickNode. Now let’s move to the next part! Hope this was really easy for you to understand!</p><ul><li>Go to your Metamask wallet and click on the list of networks.</li></ul><p></p><figure class="image"><div class="se-component se-image-container __se__float-none" contenteditable="false"><figure class="image" style="margin: 0px;"><img src="https://lh5.googleusercontent.com/2UexuPf9TiOmgJskf1KjXbksBlQwnTvRS0tU_nzrKg_3wc4hzVAX4SDqifH3y8YyTb2YJIb2NVQEF_ShIkATyplBcz5_zrzxWuKkodQs5h2JJhUWuo4I0kIRECG1evY510WYAJlbc6W9DyTBVb3gCn9KYAi8ECYR_4tMGer7RBrxErQ8-PpNpOYCrNYj6FrRWD5LrQ" data-origin="," alt="" data-proportion="true" data-align="none" data-file-name="2UexuPf9TiOmgJskf1KjXbksBlQwnTvRS0tU_nzrKg_3wc4hzVAX4SDqifH3y8YyTb2YJIb2NVQEF_ShIkATyplBcz5_zrzxWuKkodQs5h2JJhUWuo4I0kIRECG1evY510WYAJlbc6W9DyTBVb3gCn9KYAi8ECYR_4tMGer7RBrxErQ8-PpNpOYCrNYj6FrRWD5LrQ" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" data-size="," data-percentage="auto,auto" style="" data-index="2"></figure></div></figure><p></p><ul><li>A drop-down list will show up with a list of networks but you need to click on&nbsp;<strong>ADD NETWORK</strong> at the bottom of the list</li><li>Now you will have a form to fill up to add a new network to your metamask account</li><li>Let’s go back to QuickNode Endpoint Dashboard, and copy the HTTPS</li></ul><p></p><figure class="image"><div class="se-component se-image-container __se__float-none" contenteditable="false"><figure class="image" style="margin: 0px;"><img src="https://lh3.googleusercontent.com/rVD2taxs_lfShmW29I27PatQTIx9NZLnBIA3nGnyKye4Q2WQM_tiC8XpeWHCxu5g6irMWCZm6TnD3LqFhrcmwCFIWXAlnqrPoTmBB8XSiaDerKm7PvbNy625amuVm-vutlS8uyb8A1V0RxEdmtDEKDRaq_4X70LClb42guWZVyX-XCrm7htvkcFPwDAPDJMN2acgbg" data-origin="," alt="" data-proportion="true" data-align="none" data-file-name="rVD2taxs_lfShmW29I27PatQTIx9NZLnBIA3nGnyKye4Q2WQM_tiC8XpeWHCxu5g6irMWCZm6TnD3LqFhrcmwCFIWXAlnqrPoTmBB8XSiaDerKm7PvbNy625amuVm-vutlS8uyb8A1V0RxEdmtDEKDRaq_4X70LClb42guWZVyX-XCrm7htvkcFPwDAPDJMN2acgbg" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" data-size="," data-percentage="auto,auto" style="" data-index="3"></figure></div></figure><p></p><p>Now let’s go back to the Metamask add network form and&nbsp;</p><ul><li>Paste the HTTPS in&nbsp;<strong>New RPC Url</strong> field with 5 as&nbsp;<strong>Chain ID</strong>,&nbsp;</li><li>“ETH” as&nbsp;<strong>Currency Symbol</strong>,&nbsp;</li><li>Ethereum Goerli as&nbsp;<strong>Network Name (Any name as you like)</strong> and&nbsp;</li><li>Finally&nbsp;<a href="https://goerli.etherscan.io/%20"><u>https://goerli.etherscan.io/</u></a> as&nbsp;<strong>Block Explorer URL.</strong>&nbsp;</li><li>Click Save</li></ul><p></p><figure class="image"><div class="se-component se-image-container __se__float-none" contenteditable="false"><figure class="image" style="margin: 0px;"><img src="https://lh3.googleusercontent.com/NxmZPfEJiinySOv3C9APrka5wQATNH-_6XZr2ncTwDNEP6R7liepAkwQ1ApvGZGKVO3pKAndmI7X1SFyO88LrkTmL19pTlIvSZ1xsaXGjZaOo7VTUb7NLorC1Lp3wDjUXkK1oYqLlMsq94NBPDE6Ejv5Z7UvKmG80YMlZ8fQZSMGJ48Xvin122CSeYhDFckwB3wXiA" data-origin="," alt="" data-proportion="true" data-align="none" data-file-name="NxmZPfEJiinySOv3C9APrka5wQATNH-_6XZr2ncTwDNEP6R7liepAkwQ1ApvGZGKVO3pKAndmI7X1SFyO88LrkTmL19pTlIvSZ1xsaXGjZaOo7VTUb7NLorC1Lp3wDjUXkK1oYqLlMsq94NBPDE6Ejv5Z7UvKmG80YMlZ8fQZSMGJ48Xvin122CSeYhDFckwB3wXiA" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" data-size="," data-percentage="auto,auto" style="" data-index="4"></figure></div></figure><p></p><h4>&nbsp;</h4><h4>Get some fake ETH $$ 🤑</h4><p>Try the following websites and try to get some fake ETHs. This fake money will be used for deploying your contract and doing transactions on your contract. This is not real money, you can’t buy NFTs, or other assets via these ETH.&nbsp;<br><br>All you have to do is to drop your public address on the following links and the ETH will be transferred.</p><p>🔥 <a href="https://goerlifaucet.com/" target="_blank" rel="noopener noreferrer"><u>https://goerlifaucet.com/</u></a></p><h4>Get your private 🦊 MetaMask key</h4><p>Open the Metamask extension to find your private key. While writing and deploying your contract you sign off each contract with your private key to tell the blockchain that you are a legit person creating a real transaction. Now if that private key is made visible, the hacker can gain access to your account and then the rest will be history.</p><p></p><figure class="image"><div class="se-component se-image-container __se__float-none" contenteditable="false"><figure class="image" style="margin: 0px;"><img src="https://metaschool.s3-ap-southeast-1.amazonaws.com/images/xR90oDFgwFLgOIN03aIlqFhEpxUhF7R0sS9aBFCR.png" data-origin="," alt="" data-proportion="true" data-align="none" data-file-name="xR90oDFgwFLgOIN03aIlqFhEpxUhF7R0sS9aBFCR.png" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" data-size="," data-percentage="auto,auto" style="" data-index="5"></figure></div></figure><p></p><p>I will tell you how to keep your account and private key safe in the next steps. For now, export the private key and paste it somewhere secure. DON'T COMMIT IT ON GITHUB, DON'T SHARE IT ON DISCORD, DON'T SHARE IT ANYWHERE! IF YOUR KEY IS PUBLIC, HACKERS AND STEALERS WILL TAKE ALL YOUR FUND AND EVERYTHING THAT IS ASSOCIATED WITH THAT ACCOUNT.</p><p>BE EXTRAAA VIGILANT!!</p><h2>Video Walkthrough!</h2><p></p><figure class="media"><div data-oembed-url="https://www.loom.com/share/5d899234b562408fa0d1d69fe3c56ca3?sharedAppSource=personal_library"><div class="se-component se-video-container __se__float-" contenteditable="false" style="width: 100%;"><figure style="width: 100%; height: 100%; padding-bottom: 100%; margin: 0px;"><iframe src="https://www.loom.com/embed/5d899234b562408fa0d1d69fe3c56ca3" data-percentage="100%,100%" data-size="100%,100%" data-align="" data-file-name="5d899234b562408fa0d1d69fe3c56ca3" data-file-size="0" data-origin="100%,100%" style="position: absolute; width: 100%; height: 100%; top: 0; left: 0;" data-index="0"></iframe></figure></div><div style="position: relative; padding-bottom: 100%; height: 0; "><br></div></div></figure><p></p>

﻿# Setting up

Let’s get to setting up the environment first.

1. We will install and set up our metamask account.
2. We will create an alchemy app.

## Creating alchemy ⛓ app

Alchemy gives you the ability to read and write on the blockchain via their infrastructure. It saves you time. It saves you money and keeps things efficient. Let’s sign up at Alchemy, get your free account, and follow the instructions below.

[Sign up](https://auth.alchemyapi.io/signup?redirectUrl=https%3A%2F%2Fdashboard.alchemyapi.io%2Fsignup%2F) for your free account and get to create an app.

1.  Chain - Ethereum
2.  Network - Goerli

![](https://metaschool.s3-ap-southeast-1.amazonaws.com/images/NruUxYkrWbDApoXPuK2nzFDzmZE0gnfoOdtNXOl4.png)

Your API key and HTTP address is important, save it somewhere for now, and we will use it in our project later.

![](https://lh3.googleusercontent.com/GCh8lNY9s3lIBMPUX9-HdalprHLxldLq5KDzrq_9UmZXR1wixjsFIYv6JaBmFGN9pCY0vI4FrS8dLs_1HoxfHN2EUVrxCmkTGzI1_QCWH8gw-an-uCG9MU4WilBiJGzPKa54TTA3)

## Creating MetaMask wallet

Your metamask wallet is your key to the web3 world. You can interact with the blockchain via a MetaMask account. And of course, generally, it is your digital wallet to store, swap and buy cryptocurrencies, tokens, NFTs, and other amazing things in the web3 world.

MetaMask has a mobile application and a Chrome browser extension too. I personally use MetaMask on my Chrome browser extension because I do most of the work on my laptop.

Anyways, let’s go!

Here are the installation steps:

- Go to [MetaMask.io](https://metamask.io/)
- Click Download and Install the Chrome Extension.
- Setup your secure password.
- The next step is the most important one.
- Secure your 12-word phrase properly, never share it with anyone. Write it somewhere because if you lose it, you will never have a way to recover your account. So be mindful of that.

Congrats! your account is created and you must have received a public address. The public address will be in the pattern of:

_Example: 0x37EA9984481459885141F571907992e7261E837C_

You can use this public address to buy, trade, and store Ethereum based tokens, cryptos, NFTs and you can even use it to sign in to websites like OpenSea. But are you wondering if it is safe to share this cryptic long address?

Yes, it is completely safe. You can share this address publicly to accept, buy, trade or store Ethereum based crypto.

## Changing your network on MetaMask

We will not be using the live/production environment at the moment because it will be expensive to deploy a contract. You will need some real ETH to do that! And of course, learning and deploying contracts on production for the purpose of learning is not sustainable. We will switch to Goerli Network, which is a test network that pretty much is a simulation of Ethereum blockchain production. Just open chrome and switch your network to Goerli, if you are not able to see it.

![](https://metaschool.s3-ap-southeast-1.amazonaws.com/images/FWxQXFSjxMyeasV0xvKZfQjWWh1Phg6nLOr95viK.png)

Here are the steps to turn on test networks

1.  Go to settings
2.  Open Advanced
3.  Scroll down to Show Test Networks
4.  Turn on

![](https://lh3.googleusercontent.com/J1aA9vZcf8gE3h9ypNI2nQ0-wRypnCCCwNBDHtc7C9qcyzlkbOmlb6IDUxxN1xIwQpfIwSPZrmXy-C5hS65lcFIKg5U0LZaXhGw_y2QxGurmhwZSHcJwK0gk5KCaUpu45pmz8jl2)

## Get some fake ETH $$

Try the following website and try to get some fake ETHs. This fake money will be used for deploying your contract and doing transactions on your contract. This is not real money, you can’t buy NFTs, or other assets via these ETH.

All you have to do is to drop your public address on the following links and the ETH will be transferred.

1.  [https://goerlifaucet.com/](https://goerlifaucet.com/)

## Get your private MetaMask key

Open the metamask extension to find your private key. While writing and deploying your contract you sign off each contract with your private key to tell the blockchain that you are a legit person creating a real transaction. Now if that private key is made visible, the hacker can gain access to your account and then the rest will be history.

![](https://metaschool.s3-ap-southeast-1.amazonaws.com/images/xR90oDFgwFLgOIN03aIlqFhEpxUhF7R0sS9aBFCR.png)

I will tell you how to keep your account and private key safe in the next steps. For now, export the private key and paste it somewhere secure. DON'T COMMIT IT ON GITHUB, DON'T SHARE IT ON DISCORD, DON'T SHARE IT ANYWHERE! IF YOUR KEY IS PUBLIC, HACKERS AND STEALERS WILL TAKE ALL YOUR FUND AND EVERYTHING THAT IS ASSOCIATED WITH THAT ACCOUNT.

BE EXTRAAA VIGILANT!!


https://raw.githubusercontent.com/0xmetaschool/Learning-Projects/main/Writing%20your%20first%20Hello%20World%20contract%20in%20Solidity/1.%20Setting%20up%20the%20environment/2.%20Setting%20up.md

Setting up

Setting up the environment

Now that basics are setup, we will get to writing the actual code and the fun starts here.

<p>We are getting to the meat of this project. Now we will write the code. I hope you have already installed Node to your machine, and have VScode installed.&nbsp;</p><ol><li>Install&nbsp;<a href="https://nodejs.org/en/" target="_blank" rel="noopener noreferrer"><u>node from here</u></a>.</li><li>Download&nbsp;<a href="https://code.visualstudio.com/" target="_blank" rel="noopener noreferrer"><u>VScode from here</u></a></li></ol><p>Open the terminal and run the following commands. &nbsp; &nbsp;&nbsp;</p><pre><code>mkdir Hello-Worldcd Hello-Worldlsnpm init --yesnpm install --save-dev hardhatnpx hardhat</code></pre><p>When you run the last command, you will get an option to create an Empty project with hardhat config. Do pick that and you will see something like this.</p><pre><code>888    888                      888 888               888888    888                      888 888               888888    888                      888 888               8888888888888  8888b.  888d888 .d88888 88888b.   8888b.  888888888    888     "88b 888P"  d88" 888 888 "88b     "88b 888888    888 .d888888 888    888  888 888  888 .d888888 888888    888 888  888 888    Y88b 888 888  888 888  888 Y88b.888    888 "Y888888 888     "Y88888 888  888 "Y888888  "Y888👷 Welcome to Hardhat v2.11.2 👷‍✔ What do you want to do? - Create an empty hardhat.config.js✨ Config file created ✨</code></pre><p>Now let's open in project in VScode. Open the Hardhat config file.</p><p><strong>✨ <u>Side tip : Install </u></strong><a href="https://marketplace.visualstudio.com/items?itemName=JuanBlanco.solidity" target="_blank" rel="noopener noreferrer"><strong><u>Solidity Extension</u></strong></a><strong><u> by Juan Blanco in VScode to help with syntax and coding error issues.</u></strong></p><pre><code>/*** @type import('hardhat/config').HardhatUserConfig*/module.exports = {    solidity: "0.8.17",};</code></pre><p>There is not much going on here except for we are mentioning the version of solidity we are using.&nbsp;</p><h4>Creating Directories for Code</h4><p>Now we will create two directories - contracts &amp; scripts.</p><p>The contracts directory will have all the contracts for the project and scripts directory will have all the deployments scripts and other stuff related to the project. By now the structure of your project will look something like this.</p><pre><code>Hello-World&gt; contracts&gt; node_modules&gt; scriptshardhat.config.jspackage-lock.jsonpackage.json</code></pre><p>The contracts directory will have the contract of your Hello World. Create a HelloWorld.sol file in the contracts folder and write the following code.&nbsp;</p><pre><code>// SPDX-License-Identifier: UNLICENSED pragma solidity ^0.8.4; contract HelloWorld {    //events    //states    //functions     event messagechanged(string oldmsg, string newmsg);     string public message;     constructor(string memory firstmessage) {        message = firstmessage;       }     function update(string memory newmesssage) public {        string memory oldmsg = message;        message = newmesssage;         emit messagechanged(oldmsg, newmesssage);     }}</code></pre><p>We start with mentioning the version of the solidity that we are using and then write the actual contract. A smart contract has states, functions and events.&nbsp;</p><ul><li>The states are usually variables, tokens, NFTs whose state we want to maintain in the contract.</li><li>In order to read, write or change the states, we use functions.&nbsp;&nbsp;</li><li>Events are triggers that are activated based on a transformation in a state, a call to a function etc. So our code right now has a state variable called ‘message’, a function called ‘update’ and and event called ‘messagechanged’.</li></ul><p>This is a basic HelloWorld code that takes a string when the smart contract is first time executed and if we want we can change that value to a new message as well.</p><p>Now that we have written the contract, the next step is to prepare for the deployment.&nbsp;</p><h2>Video Walkthrough</h2><p></p><figure class="media"><div data-oembed-url="https://www.loom.com/share/60dfe71639bd446c980fbbab3e39df61?sharedAppSource=personal_library"><div class="se-component se-video-container __se__float-" contenteditable="false" style="width: 100%;"><figure style="width: 100%; height: 100%; padding-bottom: 100%; margin: 0px;"><iframe src="https://www.loom.com/embed/60dfe71639bd446c980fbbab3e39df61" data-percentage="100%,100%" data-size="100%,100%" data-align="" data-file-name="60dfe71639bd446c980fbbab3e39df61" data-file-size="0" data-origin="100%,100%" style="position: absolute; width: 100%; height: 100%; top: 0; left: 0;" data-index="0"></iframe></figure></div><div style="position: relative; padding-bottom: 100%; height: 0; "><br></div></div></figure><p></p>

﻿# Writing the solidity contract

We are getting to the meat of this project. Now we will write the code. I hope you have already installed Node to your machine, and have VScode installed.

1.  Install [node from here](https://nodejs.org/en/).
2.  Download [VScode from here](https://code.visualstudio.com/)

Open the terminal and run the following commands.

```bash
mkdir Hello-World
cd Hello-World
ls
npm init --yes
npm install --save-dev hardhat
npx hardhat
```

When you run the last command, you will get an option to create an Empty project with hardhat config. Do pick that and you will see something like this.

```
888    888                      888 888               888
888    888                      888 888               888
888    888                      888 888               888
8888888888  8888b.  888d888 .d88888 88888b.   8888b.  888888
888    888     "88b 888P"  d88" 888 888 "88b     "88b 888
888    888 .d888888 888    888  888 888  888 .d888888 888
888    888 888  888 888    Y88b 888 888  888 888  888 Y88b.
888    888 "Y888888 888     "Y88888 888  888 "Y888888  "Y888

👷 Welcome to Hardhat v2.11.2 👷‍

? What do you want to do? - Create an empty hardhat.config.js
✨ Config file created ✨
```

Now let's open the project in VScode. Open the Hardhat config file.

**✨ Side tip : Install [Solidity Extension](https://marketplace.visualstudio.com/items?itemName=JuanBlanco.solidity) by Juan Blanco in VScode to help with syntax and coding error issues.**

```go
/** @type import('hardhat/config').HardhatUserConfig */
module.exports = {
  solidity: "0.8.17",
};
```

There is not much going on here except for we are mentioning the version of solidity we are using.

## Creating Directories for Code

Now we will create two directories - contracts & scripts.

The contracts directory will have all the contracts for the project and scripts directory will have all the deployments scripts and other stuff related to the project. By now the structure of your project will look something like this.

```
Hello-World
 > contracts
 > node_modules
 > scripts
 hardhat.config.js
 package-lock.json
 package.json
```

The contracts directory will have the contract of your Hello World. Create a HelloWorld.sol file in the contracts folder and write the following code.

```go
// SPDX-License-Identifier: UNLICENSED

pragma solidity ^0.8.4;

contract HelloWorld {
    //events
    //states
    //functions

    event messagechanged(string oldmsg, string newmsg);

    string public message;

    constructor(string memory firstmessage) {
        message = firstmessage;
    }

    function update(string memory newmesssage) public {
        string memory oldmsg = message;
        message = newmesssage;

        emit messagechanged(oldmsg, newmesssage);

    }
}
```

We start with mentioning the version of the solidity that we are using and then write the actual contract. A smart contract has states, functions and events.

- The states are usually variables, tokens, NFTs whose state we want to maintain in the contract.
- In order to read, write or change the states, we use functions.
- Events are triggers that are activated based on a transformation in a state, a call to a function etc. So our code right now has a state variable called ‘message’, a function called ‘update’ and and event called ‘messagechanged’.

This is a basic HelloWorld code that takes a string when the smart contract is first time executed and if we want we can change that value to a new message as well.

Now that we have written the contract, the next step is to prepare for the deployment.


https://raw.githubusercontent.com/0xmetaschool/Learning-Projects/main/Writing%20your%20first%20Hello%20World%20contract%20in%20Solidity/2.%20Writing%20the%20actual%20code/Writing%20the%20solidity%20contract.md

Writing the solidity contract

Writing the actual code

In this section, we will cover the scripts needed to deploy smart contracts on the blockchain network.

<p>First let’s do some basic housekeeping stuff. We know that there are massive scams and security issues happening in the crypto world. You make a mistake and it can cost you a life time.</p><p>While writing and deploying your contract you sign off each contract with your private key to tell the blockchain that you are a legit person creating a real transaction. Now if that private key is made visible, the hacker can gain access to your account and then the rest will be history. In order to avoid this issue. Let’s do the following.</p><pre><code>npm install dotenv --savetouch .gitignore</code></pre><p>Now go ahead and create .env file at the base of your project. Open your .gitignore file and write .env there.</p><p>All the secrets and important keys related to your project will be stored in .env file and we can access this data whenever and wherever. In the gitignore file we simply write .env, it tells git to ignore that file from future commits.</p><p>Open the .env file you have just created. Add your MetaMask Private Key and Alchemy App HTTP URL there. Should be something like this.</p><pre><code>PRIVATE_KEY=YOUR_PRIVATE_KEYAPI_URL_KEY=YOUR_ALCHEMY_APP_URLAPI_KEY=YOUR_API_KEY</code></pre><p>We will update our hardhat config file to setup Goerli Deployment.</p><pre><code>/** * @type import('hardhat/config').HardhatUserConfig */require('dotenv').config(); //all the key value pairs are being made available due to this librequire('@nomiclabs/hardhat-ethers'); const {API_URL_KEY, PRIVATE_KEY} = process.env; //environment variables are being loaded here. module.exports = {  solidity: "0.8.17",  defaultNetwork: 'goerli',  networks: {    hardhat: {},    goerli: {        url: API_URL_KEY,        accounts: [`0x${PRIVATE_KEY}`]    }  }};</code></pre><p>This code is setting up some configurations for a tool called Hardhat, which helps with developing Ethereum applications. It's using a library called dotenv to load some special values called "environment variables" from a file on the computer. These environment variables are named API_URL_KEY and PRIVATE_KEY, and they'll be used in a minute.</p><p>The code is also bringing in another library called hardhat-ethers, which gives some extra helpful functions for working with Ethereum accounts and smart contracts.</p><p>Finally, the code sets up an object with some values that Hardhat can use. There's a version of a programming language called Solidity that's specified, and a default network for Hardhat to use. There's also a configuration for a specific network called goerli, which tells Hardhat what Ethereum node to connect to and what account to use on that network. The account is specified by its private key, which was one of the environment variables that was loaded earlier.</p>

﻿# Getting Ready for Deployment

First let’s do some basic housekeeping stuff. We know that there are massive scams and security issues happening in the crypto world. You make a mistake and it can cost you a life time.

While writing and deploying your contract you sign off each contract with your private key to tell the blockchain that you are a legit person creating a real transaction. Now if that private key is made visible, the hacker can gain access to your account and then the rest will be history. In order to avoid this issue. Let’s do the following.

```bash
npm install dotenv --save
touch .gitignore
```

Now go ahead and create .env file at the base of your project. Open your .gitignore file and write .env there.

All the secrets and important keys related to your project will be stored in .env file and we can access this data whenever and wherever. In the gitignore file we simply write .env, it tells git to ignore that file from future commits.

Open the .env file you have just created. Add your MetaMask Private Key and Alchemy App HTTP URL there. Should be something like this.

```
PRIVATE_KEY=YOUR_PRIVATE_KEY
API_URL_KEY=YOUR_ALCHEMY_APP_URL
API_KEY=YOUR_API_KEY
```

We will update our hardhat config file to setup Goerli Deployment.

```js
/**
 * @type import('hardhat/config').HardhatUserConfig
 */
require("dotenv").config(); //all the key value pairs are being made available due to this lib
require("@nomiclabs/hardhat-ethers");

const { API_URL_KEY, PRIVATE_KEY } = process.env; //environment variables are being loaded here.

module.exports = {
  solidity: "0.8.17",
  defaultNetwork: "goerli",
  networks: {
    hardhat: {},
    goerli: {
      url: API_URL_KEY,
      accounts: [`0x${PRIVATE_KEY}`],
    },
  },
};
```

This code is setting up some configurations for a tool called Hardhat, which helps with developing Ethereum applications. It's using a library called dotenv to load some special values called "environment variables" from a file on the computer. These environment variables are named API_URL_KEY and PRIVATE_KEY, and they'll be used in a minute.

The code is also bringing in another library called hardhat-ethers, which gives some extra helpful functions for working with Ethereum accounts and smart contracts.

Finally, the code sets up an object with some values that Hardhat can use. There's a version of a programming language called Solidity that's specified, and a default network for Hardhat to use. There's also a configuration for a specific network called goerli, which tells Hardhat what Ethereum node to connect to and what account to use on that network. The account is specified by its private key, which was one of the environment variables that was loaded earlier.


https://raw.githubusercontent.com/0xmetaschool/Learning-Projects/main/Writing%20your%20first%20Hello%20World%20contract%20in%20Solidity/3.%20Preparing%20for%20Deployment/1.%20Getting%20Ready%20for%20Deployment.md

Getting Ready for Deployment

<p>Now is the time to write the deployment script. Now, we will create a deploy.js file in the scripts folder and this file will contain all the logic for deployment. Before that we run the following command in the terminal.</p><pre><code>npm install --save-dev @nomiclabs/hardhat-ethers</code></pre><p>Hardhat ethers is a plugin that gives us access to ethers.js library. Ethers.js library gives us a way to interact with the blockchain world, we can deploy contracts, we can fetch contracts, we can call their functions, all thanks to this library.</p><p>Your deploy.js file will look like this.</p><pre><code>const { ethers } = require("hardhat");async function main() {    const HelloWorld = await ethers.getContractFactory('HelloWorld');    const hw = await HelloWorld.deploy("Hello World! Bingo");    console.log('Contract Deployed to:', hw.address);} main().then(() =&gt; process.exit(0)).catch(error =&gt; { console.error(error); process.exit(1);});</code></pre><p>The first line is bringing in a special part of the Hardhat library called "ethers", which gives some helpful functions for working with Ethereum.</p><p>The next part is a function called main, which is going to contain the steps to deploy the smart contract. Inside of the main function, there's a line of code that gets the "contract factory" for a smart contract called "HelloWorld". A contract factory is kind of like a template for a smart contract, and it lets us create new instances of the contract.</p><p>Then, the code creates a new instance of the "HelloWorld" contract and stores it in a variable called hw. The hw variable will be a copy of the "HelloWorld" contract, but it will live on the Ethereum blockchain at a specific address.</p><p>Finally, the code logs the address of the deployed contract to the console, and then the function is set up to finish and exit the program.</p><p>I hope that helps! Let me know if you have any questions.</p><p><strong>Booooooommmmmmmm!!! 🚀🚀🚀🚀 We are ready for deployment. Run the following command.</strong></p><pre><code>npx hardhat run scripts/deploy.js --network goerli</code></pre><p>If all goes well, your contract will be deployed and you will be able to see the address of the contract on the terminal. <strong>🔮🔮Copy that and save in your .env file with variable name as CONTRACT_ADDRESS, we will use it later to interact with the contract.</strong></p><p>Now your .env file should look something like this</p><pre><code>PRIVATE_KEY=YOUR_PRIVATE_KEYAPI_URL_KEY=YOUR_API_URL_KEYAPI_KEY=YOUR_API_KEYCONTRACT_ADDRESS=YOUR_DEPLOYED_CONTRACT_ADDRESS</code></pre><p>Congratulations!! Congratulations!! Congratulations!!</p><p>Your contract is deployed. ⛺️🚀⛺️🚀⛺️</p><p>A cool thing you can do right now is go to <a href="https://goerli.etherscan.io/">goerli.etherscan.io</a> and copy paste your contract and read more about it.</p><p>🔥🔥🔥🔥 Etherscan is <strong>a website to help you view data regarding any pending or confirmed Ethereum blockchain transactions.</strong> Since Ethereum is a public, open blockchain, whenever anyone interacts with it the action is recorded into the transaction history and it is open for anyone to see.</p>

﻿# Writing Deployment Script

Now is the time to write the deployment script. Now, we will create a deploy.js file in the scripts folder and this file will contain all the logic for deployment. Before that we run the following command in the terminal.

```bash
npm install --save-dev @nomiclabs/hardhat-ethers
```

Hardhat ethers is a plugin that gives us access to ethers.js library. Ethers.js library gives us a way to interact with the blockchain world, we can deploy contracts, we can fetch contracts, we can call their functions, all thanks to this library.

Your deploy.js file will look like this.

```js
const { ethers } = require("hardhat");
async function main() {
  const HelloWorld = await ethers.getContractFactory("HelloWorld");

  const hw = await HelloWorld.deploy("Hello World! Bingo");

  console.log("Contract Deployed to:", hw.address);
}

main()
  .then(() => process.exit(0))
  .catch((error) => {
    console.error(error);
    process.exit(1);
  });
```

The first line is bringing in a special part of the Hardhat library called "ethers", which gives some helpful functions for working with Ethereum.

The next part is a function called main, which is going to contain the steps to deploy the smart contract. Inside of the main function, there's a line of code that gets the "contract factory" for a smart contract called "HelloWorld". A contract factory is kind of like a template for a smart contract, and it lets us create new instances of the contract.

Then, the code creates a new instance of the "HelloWorld" contract and stores it in a variable called hw. The hw variable will be a copy of the "HelloWorld" contract, but it will live on the Ethereum blockchain at a specific address.

Finally, the code logs the address of the deployed contract to the console, and then the function is set up to finish and exit the program.

I hope that helps! Let me know if you have any questions.

**Booooooommmmmmmm!!! 🚀 We are ready for deployment. Run the following command.**

```bash
npx hardhat run scripts/deploy.js --network goerli
```

If all goes well, your contract will be deployed and you will be able to see the address of the contract on the terminal. **🔮 Copy that and save in your .env file with variable name as CONTRACT_ADDRESS, we will use it later to interact with the contract.**

Now your .env file should look something like this

```bash
PRIVATE_KEY=YOUR_PRIVATE_KEY
API_URL_KEY=YOUR_API_URL_KEY
API_KEY=YOUR_API_KEY
CONTRACT_ADDRESS=YOUR_DEPLOYED_CONTRACT_ADDRESS
```

Congratulations!! Congratulations!! Congratulations!!

Your contract is deployed. 🚀

A cool thing you can do right now is go to [goerli.etherscan.io](https://goerli.etherscan.io/) and copy paste your contract and read more about it.

🔥 Etherscan is **a website to help you view data regarding any pending or confirmed Ethereum blockchain transactions.** Since Ethereum is a public, open blockchain, whenever anyone interacts with it the action is recorded into the transaction history and it is open for anyone to see.


https://raw.githubusercontent.com/0xmetaschool/Learning-Projects/main/Writing%20your%20first%20Hello%20World%20contract%20in%20Solidity/3.%20Preparing%20for%20Deployment/2.%20Writing%20Deployment%20Script.md

Writing Deployment Script

<p>In the same scripts folder, create a new file interact.js. And add the following code.</p><pre><code>const { ethers } = require("hardhat"); const API_KEY = process.env.API_KEY; //get from alchemyconst CONTRACT_ADDRESS = process.env.CONTRACT_ADDRESS; //deployed contract addressconst PRIVATE_KEY = process.env.PRIVATE_KEY; //metamask const contract = require('../artifacts/contracts/HelloWorld.sol/HelloWorld.json'); // provider - Alchemyconst alchemyProvider = new ethers.providers.AlchemyProvider(network="rinkeby", API_KEY); // signer - youconst signer = new ethers.Wallet(PRIVATE_KEY, alchemyProvider); // contract instanceconst helloWorldContract = new ethers.Contract(CONTRACT_ADDRESS, contract.abi, signer); async function main() {     const message = await helloWorldContract.message();    console.log("the message is "+ message);     const tx = await helloWorldContract.update("Good Bye, World!");    await tx.wait();     const nmessage = await helloWorldContract.message();    console.log("the new message is "+ nmessage);} main().then(() =&gt; process.exit(0)).catch(error =&gt; {  console.error(error);  process.exit(1);});</code></pre><p>This code is using a library called Hardhat to interact with a smart contract that's already been deployed to the Ethereum blockchain.</p><p>The code starts by bringing in the ethers part of the Hardhat library, and then it loads some environment variables that were saved earlier. These variables are the API_KEY, which is used to connect to the Ethereum blockchain, the CONTRACT_ADDRESS, which is the location of the smart contract on the blockchain, and the PRIVATE_KEY, which is the private key for an Ethereum account on MetaMask that's going to be used to sign transactions.</p><p>The code then brings in the contract's ABI (which stands for "Application Binary Interface") and some other information about the contract from a JSON file. The ABI is like a set of instructions for interacting with the contract, and it's needed to create an instance of the contract.</p><p>Next, the code sets up a provider to connect to the Ethereum blockchain using the API_KEY, and then it creates a "signer" object using the PRIVATE_KEY and the provider. The signer will be used to sign transactions that are sent to the contract.</p><p>Then, the code creates an instance of the smart contract using the CONTRACT_ADDRESS, the contract's ABI, and the signer. This gives us a way to call functions on the contract and send transactions to it.</p><p>The main function is then defined. It starts by calling a function on the contract called message to get the current message that's stored in the contract. It then logs this message to the console.</p><p>The code then sends a transaction to the contract to update the message to a new value, using the update function on the contract instance. It waits for this transaction to be processed by the Ethereum network before moving on.</p><p>Finally, the main function calls the message function again to get the updated message, and then it logs the new message to the console.</p><pre><code>npx hardhat run scripts/interact.js --network goerli</code></pre><p>You will see something like this.</p><pre><code>the message is Hello World! Bingothe new message is Good Bye, World!</code></pre><p>Massive congrats! You have made it! You are done. In this course, we learned about:</p><ol><li>Setting up MetaMask<ol style="list-style-type:lower-roman;"><li>Switching Networks</li><li>Getting some Fake eth</li></ol></li><li>Setting up Alchemy App</li><li>Writing your first contract</li><li>Deploying your solidity contract</li><li>Interacting with your contract</li></ol>

﻿# Interacting with the Deployed Contract.

In the same scripts folder, create a new file interact.js. And add the following code.

```js
const { ethers } = require("hardhat");

const API_KEY = process.env.API_KEY; //get from alchemy
const CONTRACT_ADDRESS = process.env.CONTRACT_ADDRESS; //deployed contract address
const PRIVATE_KEY = process.env.PRIVATE_KEY; //metamask

const contract = require("../artifacts/contracts/HelloWorld.sol/HelloWorld.json");

// provider - Alchemy
const alchemyProvider = new ethers.providers.AlchemyProvider(
  (network = "goerli"),
  API_KEY
);

// signer - you
const signer = new ethers.Wallet(PRIVATE_KEY, alchemyProvider);

// contract instance
const helloWorldContract = new ethers.Contract(
  CONTRACT_ADDRESS,
  contract.abi,
  signer
);

async function main() {
  const message = await helloWorldContract.message();
  console.log("the message is " + message);

  const tx = await helloWorldContract.update("Good Bye, World!");
  await tx.wait();

  const nmessage = await helloWorldContract.message();
  console.log("the new message is " + nmessage);
}

main()
  .then(() => process.exit(0))
  .catch((error) => {
    console.error(error);
    process.exit(1);
  });
```

This code is using a library called Hardhat to interact with a smart contract that's already been deployed to the Ethereum blockchain.

The code starts by bringing in the ethers part of the Hardhat library, and then it loads some environment variables that were saved earlier. These variables are the API_KEY, which is used to connect to the Ethereum blockchain, the CONTRACT_ADDRESS, which is the location of the smart contract on the blockchain, and the PRIVATE_KEY, which is the private key for an Ethereum account on MetaMask that's going to be used to sign transactions.

The code then brings in the contract's ABI (which stands for "Application Binary Interface") and some other information about the contract from a JSON file. The ABI is like a set of instructions for interacting with the contract, and it's needed to create an instance of the contract.

Next, the code sets up a provider to connect to the Ethereum blockchain using the API_KEY, and then it creates a "signer" object using the PRIVATE_KEY and the provider. The signer will be used to sign transactions that are sent to the contract.

Then, the code creates an instance of the smart contract using the CONTRACT_ADDRESS, the contract's ABI, and the signer. This gives us a way to call functions on the contract and send transactions to it.

The main function is then defined. It starts by calling a function on the contract called message to get the current message that's stored in the contract. It then logs this message to the console.

The code then sends a transaction to the contract to update the message to a new value, using the update function on the contract instance. It waits for this transaction to be processed by the Ethereum network before moving on.

Finally, the main function calls the message function again to get the updated message, and then it logs the new message to the console.

```bash
npx hardhat run scripts/interact.js --network goerli
```

You will see something like this.

```
the message is Hello World! Bingo
the new message is Good Bye, World!
```

Massive congrats! You have made it! You are done. In this course, we learned about:

1.  Setting up MetaMask
    1.  Switching Networks
    2.  Getting some Fake eth
2.  Setting up Alchemy App
3.  Writing your first contract
4.  Deploying your solidity contract
5.  Interacting with your contract


https://raw.githubusercontent.com/0xmetaschool/Learning-Projects/main/Writing%20your%20first%20Hello%20World%20contract%20in%20Solidity/3.%20Preparing%20for%20Deployment/3.%20Interacting%20with%20the%20Deployed%20Contract..md

Writing your first Hello World contract in Solidity

Project Curriculum

Setting up the environment

Writing the actual code

Preparing for Deployment

🎉 Completion

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