call: Warning: Unused local variable

Question

I am trying to compile the following code:

pragma solidity ^0.5.1;

contract MKotET1_1{
   address payable king; uint public claimPrice = 100;

   function calculateCompensation() public returns(uint) {
}

function( ) external payable {
   if (msg.value  < claimPrice) revert();
      uint compensation = calculateCompensation();
      (bool success, bytes memory returnMessage) = 
      king.call.value(compensation)("");
      require(success); 
      king = msg.sender;
   }
}

I am getting following warning message:

solc MKotET_stackExchange.sol MKotET_stackExchange.sol:11:26: Warning: Unused local variable. (bool success, bytes memory returnMessage) = king.call.value(compensation)(""); ^------------------------^

Somebody please guide me how to remove this warning message.

Zulfi.

Answer 1

You do not need to explicitly state the second variable declaration. You can write it as follows:

(bool success, ) = king.call.value(compensation)("");
require(success);