智能合约是区块链不可或缺的一部分。这些合约是指在满足特定条件的情况下，在两个或多个参与者之间执行特定任务的软件程序。本质上，它就像一个自动执行的常规合约，不需要中介，因为它依赖于它的编程值系统開发180-383 I-9724。****
pragma solidity ^0.4.0;
import "./ERC20Interface.sol";
contract ERC20 is ERC20Interface{
string private _name = "MyToken";
string private _symbol = "MYT";
uint8 private _decimals = 3;
uint256 private _totalSupply = 10 * (10 ** uint256(_decimals));
mapping(address=>uint256) private _balances;
mapping(address=>mapping(address=>uint256)) private _allowances;
event Transfer(address indexed _from, address indexed _to, uint256 _value);
event Approval(address indexed _owner, address indexed _spender, uint256 _value);
function ERC20(){
_balances[msg.sender] = _totalSupply;
}
function name() public view returns (string name){
name = _name;
}
function symbol() public view returns (string symbol){
symbol = _symbol;
}
function decimals() public view returns (uint8 decimals){
decimals = _decimals;
}
function totalSupply() public view returns (uint256 totalSupply){
totalSupply = _totalSupply;
}
function balanceOf(address _owner) public view returns (uint256 balance){
balance = _balances[_owner];
}
function transfer(address _to, uint256 _value) public returns (bool success){
require(_balances[msg.sender] >= _value);
_balances[msg.sender] -= _value;
_balances[_to] += _value;
Transfer(msg.sender, _to, _value);
success = true;
}
function transferFrom(address _from, address _to, uint256 _value) public returns (bool success){
require(_balances[_from] >= _value);
require(_allowances[_from][msg.sender] >= _value);
_balances[_from] -= _value;
_allowances[_from][msg.sender] -= _value;
_balances[_to] += _value;
Transfer(_from, _to, _value);
success = true;
}
function approve(address _spender, uint256 _value) public returns (bool success){
_allowances[msg.sender][_spender] = _value;
Approval(msg.sender, _spender, _value);
success = true;
}
function allowance(address _owner, address _spender) public view returns (uint256 remaining){
remaining = _allowances[_owner][_spender];
}
}
智能合约相当于使用步伐编程接口（API），但它不是在平日的web平台上应用，而是在区块链上使用。应用系统程序编程接口（API）允许学生用户在他们可以使用的平台上进行信息交互并引入某些特性。
