2023-11-30 erc20转账逻辑

下面是自己发行一个代币示例代码如下：

contract  GdLooker is IERC20{

    mapping(address => uint256) public override balanceOf;

    mapping(address => mapping(address => uint256)) public override allowance;

    uint256 public override totalSupply;   // 代币总供给

    string public name="GdLooker";   // 在钱包添加合约地址的时候该名称会立即在钱包显示
    string public symbol;  // 代号

    uint8 public decimals = 18; // 小数位数

    constructor(string memory name_, string memory symbol_){
        name = name_;
        symbol = symbol_;
    }

    function transfer(address to, uint amount) external override returns (bool) {
        balanceOf[msg.sender] -= amount;
        balanceOf[to] += amount;
        emit Transfer(msg.sender, to, amount);
        return true;
    }

    function approve(address spender, uint amount) external override returns (bool) {
        allowance[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function transferFrom(
        address sender,
        address recipient,
        uint amount
    ) external override returns (bool) {
        allowance[sender][msg.sender] -= amount;
        balanceOf[sender] -= amount;
        balanceOf[recipient] += amount;
        emit Transfer(sender, recipient, amount);
        return true;
    }
}

上面示例代码解读 transfer跟transferFrom的区别
首先 用了2个map key是作为用户的地址 value专门用来存储用户有多少币数
allowance //这个是已经授权的map 基于key(也就是钱包地址)来缓存用户在拉起钱包授权输入数量作为value值
balanceOf 是用来存储所有用户的余额