Lesson 4 - function return

[nikwilms]

I am trying to grasp the concept about this line here in the the FundMe.sol contract.
https://github.com/PatrickAlphaC/fund-me-fcc/blob/7b260e0e488596b7256d3ad6380291a830507f4b/FundMe.sol#L53

(bool callSuccess, ) = payable(msg.sender).call{value: address(this).balance}("");

The left part (bool callSuccess, ), is it something like a destructuring assignment? Because there is no return, it confuses me a bit.

[mattjaf]

In Solidity, a call (or delegatecall) returns two values that describe the status and result of the call. The first return value is a bool that states whether a call was successful or unsuccessful. The second parameter is the return data of the call, usually labeled data or res. This represents any data returned by the call.

You can read more about calls in the docs.
https://ethereum.stackexchange.com/questions/93938/variables-is-brackets

Only the bool is stored. This is common if the calling contract does not need or care about the returned value but does care about whether or not the call succeeded.

[nikwilms]

Thx, that helps a lot and makes sense now