从零教你学习ERC20智能合约｜Solidity智能合约

好的，以下是一个简单的ERC20智能合约示例： ```solidity pragma solidity ^0.8.0; contract ERC20Token { string public name; string public symbol; uint256 public totalSupply; mapping(address=> uint256) public balanceOf; mapping(address=> mapping(address=> uint256)) public allowance; constructor(string memory _name, string memory _symbol, uint256 _totalSupply) { name=_name; symbol=_symbol; totalSupply=_totalSupply; balanceOf[msg.sender]=_totalSupply; } function transfer(address _to, uint256 _value) public returns (bool success) { require(balanceOf[msg.sender] >=_value, "Insufficient balance"); balanceOf[msg.sender] -=_value; balanceOf[_to] +=_value; emit Transfer(msg.sender, _to, _value); return true; } function approve(address _spender, uint256 _value) public returns (bool success) { allowance[msg.sender][_spender]=_value; emit Approval(msg.sender, _spender, _value); return true; } function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) { require(balanceOf[_from] >=_value, "Insufficient balance"); require(allowance[_from][msg.sender] >=_value, "Insufficient allowance"); balanceOf[_from] -=_value; balanceOf[_to] +=_value; allowance[_from][msg.sender] -=_value; emit Transfer(_from, _to, _value); return true; } event Transfer(address indexed _from, address indexed _to, uint256 _value); event Approval(address indexed _owner, address indexed _spender, uint256 _value); } ``` 该合约包括以下功能： - `name`：代币名称 - `symbol`：代币符号 - `totalSupply`：代币总量 - `balanceOf`：每个地址的代币余额 - `allowance`：允许其他地址花费的代币数量 该合约实现了ERC20标准中的以下函数： - `transfer`：从调用者的地址向另一个地址发送代币 - `approve`：允许另一个地址花费指定数量的代币 - `transferFrom`：从一个地址向另一个地址发送代币，前提是已经获得了允许 该合约还定义了两个事件： - `Transfer`：代币发送时触发 - `Approval`：允许花费代币时触发 要部署这个合约，你需要使用Solidity编译器将其编译为字节码，然后将字节码发送到以太坊网络上。你可以使用Remix或Truffle等工具来编译和部署智能合约。