2. Create your own NFT collections and publish a Web3 application to show them start and run your local environment

A little introduction to blockchain

First , We need to make the local Ethereum network work properly . That is how we compile and test our smart contract code ！ Do you know how you need to start a local environment to work ？ Same thing here ！

Now? , You just need to know , A smart contract is a piece of code that exists on the blockchain . Blockchain is a public place , Blockchain is a public place , Anyone can read and write data safely for free . Think about it a bit like AWS or Heroku, Except that no one really owns it ！ It is called by thousands “ The miners ” Random person management .

The general idea here is ：

1 – We need to write a smart contract . The contract includes us NFT All the logic of .

2 – Our smart contract should be deployed on the blockchain . such , Anyone in the world can view and call our smart contract , This contract is that we will allow them to cast NFT The contract of ！

3 – We will set up a customer website , So that people can easily cast from our collection NFT.

I suggest you also read these file . in my opinion , These are the best guides on the Internet to understand how Ethereum works ！

️ Set up local tools

We will use the name Hardhat Tools for , It enables us to quickly compile smart contracts , And test locally . First , You need to get node/npm. If you don't have it , succeed in inviting sb. here .

Be careful ： I am here node 16 On . I know that some people encounter on the old version of the node “ Out of memory error ”, So if this happens , Please get node 16！

Next , Let's go terminal . Here, first create a folder locally ：epic-nfts, Go ahead and cd Go to the working directory .

The terminal runs these commands ：

mkdir epic-nfts
cd epic-nfts 
npm init -y 
npm install --save-dev hardhat

Run the last command and install Hardhat after , You may see messages about vulnerabilities . Each time from NPM When installing a software , Will carry out safety inspection , To see if there are any reported vulnerabilities in any software packages in the library you are installing . This is more like a warning to you ！ If you want to learn more , Please be there. Google Search for these vulnerabilities on ！

Then the local directory structure ：

Run the sample project

cool , Now we have hardhat 了 . Let's start a sample project .

npx hardhat

Pictured ：

Be careful ： If you are in Windows Upper use Git Bash install hardhat, You may find yourself in this step (HH1) Encounters an error . If there is a problem , You can try Windows CMD perform HardHat install . Can be in here Find other information .

Choose the option to create a basic sample project . All choose yes , That is input y.

The sample project will require you to install hardhat-waffle and hardhat-ethers. These are what we will use later .

Continue installing additional dependencies , In case it doesn't install automatically .

npm install --save-dev @nomiclabs/hardhat-waffle ethereum-waffle chai @nomiclabs/hardhat-ethers ethers

You also need to install one called OpenZeppelin The library of , This is another library for developing secure smart contracts . Later we will learn more about it in detail . Now? , Just install it .

npm install @openzeppelin/contracts

And then run sample-script.js：

Execute at the terminal ：

npx hardhat run scripts/sample-script.js

You should see the following ：

If you also display this message , It means that your local environment has been set , And you also run on the local blockchain / Deployed smart contracts .

Next, let's discuss it in detail , What just happened step by step is ：

1. Hardhat Change your smart contract from solidity Compile as bytecode .
2. Hardhat Will start on your computer “ Local blockchain ”. It's like a mini beta of Ethereum running on your computer , It can help you test things quickly ！
3. then ,Hardhat Will compile your contract “ Deploy ” To your local blockchain . That's the address you saw last . This is our contract deployed on the mini Ethereum .

If you are interested , You can check the code in the project at will , See how it works . say concretely , Check the smart contract file Greeter.sol And the actual contract documents sample-script.js.

After exploring , Let's move on to the next part and start our own NFT contract .