I am new to ethereum & blockchain technology and trying to understand somethings(Etheruem, Truffle, DApps etc.) here and there from the internet. From Ethereum official website,
I am trying to specifically understand these functions
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) {...}
and lastly this function() {throw;}
This contract code
contract tokenRecipient { function receiveApproval(address _from, uint _value, address _token, bytes _extraData); }
and this declaration mapping (address => mapping (address => uint) ) public allowance;
transfer(...)
,approve(...)
andtransferFrom(...)
functions work at theethereum.wiki/w/index.php/… .