dapp丨swap去中心化交易所系统开发实现技术详细/方案项目/案例详细/逻辑说明/源码部署

　　DApp（Decentralized Application）智能合约系统是建立在区块链技术上的应用程序，通过智能合约实现去中心化的功能和业务逻辑

　　智能合约是一种基于区块链技术的可编程合约，它能够自动执行、控制和验证交易的执行结果，而无需依赖第三方。智能合约使用智能合约语言编写，并部署在区块链网络上。通过智能合约，参与者可以在无需信任的情况下进行可靠的交易和协议执行。

function _mint(address to, uint value) internal {
    totalSupply = totalSupply.add(value);
    balanceOf[to] = balanceOf[to].add(value);
    emit Transfer(address(0), to, value);
}

function _burn(address from, uint value) internal {
    balanceOf[from] = balanceOf[from].sub(value);
    totalSupply = totalSupply.sub(value);
    emit Transfer(from, address(0), value);
}

function _approve(address owner, address spender, uint value) private {
    allowance[owner][spender] = value;
    emit Approval(owner, spender, value);
}

function _transfer(address from, address to, uint value) private {
    balanceOf[from] = balanceOf[from].sub(value);
    balanceOf[to] = balanceOf[to].add(value);
    emit Transfer(from, to, value);
}

function approve(address spender, uint value) external returns (bool) {
    _approve(msg.sender, spender, value);
    return true;
}

function transfer(address to, uint value) external returns (bool) {
    _transfer(msg.sender, to, value);
    return true;
}