24번 ETH 송금하고 받기

코드

interface BB {
    function setReceiveEtherAddress(address payable _contractAddress) external;
    function contractAddress() external returns(address payable);
}
contract BBBB {
    address payable public web3onlinejudge = payable(0x21867762b9b90EedA877a7879f86Fa655C4bE5Ef);
    event aaa(address payable);
    receive() external payable {}
    function getReceiveEtherAddress() public {
        emit aaa(BB(web3onlinejudge).contractAddress());
    }
    function setReceiveEtherAddress() public {
        BB(web3onlinejudge).setReceiveEtherAddress(payable(this));
    }
}

과정

1. 문제 컨트랙트로 임의의 ETH 전송
2. contract BBBB 배포
3. setReceiveEtherAddress() 함수 실행
4. 제출버튼 클릭

핵심

• receive function이 있어야 한다.