solidity中mapping的应用。
pragma solidity^0.4.0;
contract C{
mapping(address=>uint)public balances;
function update(uint amount) public returns(uint){
balances(msg.sender)=amount;
}
contract D{
function fun() public returns(uint){
C c = new C();
c.update(10);
return c.balances(address(this);
}
}
加油😘！