How to read partial values from a tuple?

Question

I haven't seen this question asked and answered, so I decided to post it myself.

How to read only some variables from a tuple returned by a function in Solidity?

Answer 1

It's simple! Just use commas:

/* SPDX-License-Identifier: LGPL-3.0-or-later */
pragma solidity ^0.7.1;

contract TupleTest {
    
    function foo() public pure returns (uint256 left, uint256 middle, uint256 right) {
        return (8, 16, 32);
    }
    
    function bar() external pure returns (uint256) {
        uint256 middle;
        (, middle, ) = foo();
        return middle;
    }
}

Copy-paste this into Remix and see for yourself.