我是新来的区块链技术,并试图从互联网上了解一些东西(Etheruem,松露,DApps等)在这里和那里。 从复仇官方网站,有人请详细解释这个以弗所合约正在做什么?
我想具体了解这些功能
approve(address _spender, uint _value) returns (bool success) {...}
approveAndCall(address _spender, uint _value, bytes _extraData) returns (bool success) {...}
transferFrom(address _from, address _to, uint _value) returns (bool success) {...}
,最后这个function() {throw;}
本合同代码
contract tokenRecipient { function receiveApproval(address _from, uint _value, address _token, bytes _extraData); }
和本声明mapping (address => mapping (address => uint)) public allowance;