Under the pressure of technology, you can quickly get started with eth smart contract development, which will take you into the ETH world

• Install wallet
  • install Metamask、 And create a good account
• Perform the first transfer
  • Test currency acquisition
  • First transfer
• First smart contract
  • Use Remix Create the first contract
  • Use Remix Test the first contract
  • Use Remix Deploy the first contract

Install wallet

install Metamask、 And create a good account

Metamask It is an Ethereum wallet in the virtual world , Also because of its LOGO It's a cute little fox , It's also known as “ Fox wallet ”. MetaMask Many clients , Including the mobile terminal ： The android mobile phone MetaMask The client is based on Google store , Domestic Android phones do not support , This one may be a little more troublesome , How to install , You can search for . The same goes for Apple phones , There seems to be no android in Apple stores in China , You need to register a U.S. account to download .

Then the most commonly used one is PC End , In fact, this is also the simplest , And now the mainstream Google Chrome,Microsoft Edge And other browsers can support installation , So let's start with Google Chrome Take as an example MetaMask（ Fox wallet ） How to install and register .

First of all, our network is the scientific network , If you don't understand , You can search and solve by yourself .

And then we use Google Chrome open MetaMask,https://metamask.io/, We can see MetaMask Home page for client downloads , Because there is no Chinese , We can solve this problem through translation software . But with chrome When it's opened ,Download The plug-in of the corresponding browser version will be automatically selected , Click download . Click to jump to chrome The store , Click Add to chrome After installation , Will jump to MetaMask The welcome screen , In the middle is a little fox that will follow your mouse , Isn't it interesting . Click to start using , Will let you choose whether to use it for the first time MetaMask, The first time you use it, you will create a new wallet account and account mnemonic , If it already exists , Use the account mnemonic to import the existing wallet .

Here we choose to use for the first time . Here you can choose whether to give MetaMask Provide usage data , There are similar regulations in modern software , You can choose as you like , So here I'm going to choose “ No , thank you ”.

next step , Will let you create a password , Password at least 8 Characters , For the safety of the wallet , Make it as complicated as possible .

After creation , Jump to a tutorial interface , Tell you what account mnemonics are , And his role . about MetaMask, You should keep your mnemonics well , And avoid using mnemonic words in clear text , Avoid leakage , The wallet was stolen and empty .

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After reading the tutorial , Click next , Will let you manually turn on display mnemonics , And remind you again of the importance of mnemonics . Write down and keep your mnemonic words

next step , Will let you enter mnemonic words manually , To see if it's right . Click ok ,MetaMask Your account registration is complete ,MetaMask Will remind you again of the importance of mnemonics . Write down and keep your mnemonic words Here are your MetaMask Wallet page , In the middle is what's left in everyone's wallet ETH balance , Then we can choose some intermediate platforms to buy ETH, And then everybody goes through MetaMask Go to Opensea To buy NFT There are other blockchain things to do , Next, we will perform a transfer .

in addition ：MetaMask After the installation , It can be opened through the little fox icon in the upper right corner of the browser MetaMask wallet , Small and mini .

Perform the first transfer

This time I will use the test currency to perform a transfer , Due to the present ETH The faucet is running dry , It is already very difficult to get ETH Your test coin , But there are many compatibility options ETH To test the transfer , Here I use OKTest（ Orco test network ）.

Test currency acquisition

Open orco test network address https://www.oklink.com/zh-cn/okc-test, take OK Test network added to MetaMask. After clicking , The little fox will jump out of the connection prompt window , Follow the prompts step by step . After adding the test network , There is still no test coin , Now it is difficult to get a test coin . Open the address ：https://discord.com/invite/B5nMs6qK5F, Another series of verification succeeded , Finally, I can get the test money . In the chat window , Send your wallet address , The robot will be you 10OKT

First transfer

Now you can transfer money , Click Send , Enter the wallet address of the other party , Enter the transfer currency , If the fuel price is high , It can make the transfer faster and the transaction successful , Faster generation of blocks . You can see the transfer status here Wait for a while , Transfer succeeded , You can see the transfer details on the blockchain browser . I'll introduce you to , Introduction to smart contract development .

First smart contract

Use Remix Create the first contract

Remix https://remix.ethereum.org/ Is an Ethereum smart contract language Solidity The browser version of IDE, A great development tool for beginners , And there are many official documents , Because abroad , It will be slow to open for the first time . Here is a simple smart contract for storing input values ,store Receive a number and save ,retrieve Returns the saved number .

contract Storage {

    uint256 number;

    /**
     * @dev Store value in variable
     * @param num value to store
     */
    function store(uint256 num) public {
        number = num;
    }

    /**
     * @dev Return value 
     * @return value of 'number'
     */
    function retrieve() public view returns (uint256){
        return number;
    }
}

Use Remix Test the first contract

First, let's compile , Click the toolbar button on the left , Make sure that the compilation passes Click on Deploy Button , Deploy smart contracts , Here we choose JavaScript VM Environmental Science , Develop and test in the local virtual machine environment , If deployed on the network , Every transaction costs gas Of . After successful deployment , At the bottom Deployed Contracts If the smart contract has been deployed, the smart contract with successful deployment will appear , So let's test that out . Test input 1 After storage , Get 1, Input 2 After storage , Get 2, The smart contract local development test was successful , Then it can be deployed to the test network .

Use Remix Deploy the first contract

The same is Remix, Select... From the virtual machine environment drop-down box Injected Web3, At this time, the installation will pop up MetaMask wallet , link Remix And wallets , Follow the steps . We deploy the smart contract to OKTEST The Internet , Click on Deploy, The transaction confirmation window pops up , There will be an estimated fuel cost , You can choose to edit or default , Confirm the deal . Again , After successful deployment , Little fox will pop up a reminder ,Remix Of Deployed Contracts There will also be deployed smart contracts , Let's test it . so , Every time a stored value is written , Will generate a transaction , But no transaction is generated when reading the value of .

Here we go hand in hand ETH The smart contract tutorial is over , about Remix Some simple and not very complex smart contract development is enough , The latter is what you need to learn Solidity Language , And continuously skillfully use tools and languages in the process of learning and development , So we can deal with some real projects .

If there's a chance later , We will introduce the development and testing of complex smart contracts , I'll see you again .PM:2022 year 6 month 30 Japan 03:15:52