Lesson 7: Staging Test Withdraw

[lexorrr]

Hello guys, I just want to clarify the 'payable' in the withdraw function of the FundMe contract. Why is there a payable there? Please enlighten me. Thank you!
BTW here is the code snippet:

function withdraw() public payable onlyOwner {
        for (
            uint256 funderIndex = 0;
            funderIndex < s_funders.length;
            funderIndex++
        ) {
            address funder = s_funders[funderIndex];
            s_addressToAmountFunded[funder] = 0;
        }
        // reset the array
        s_funders = new address[](0);

        // actually withdraw the funds

        // transfer
        // msg.sender = address
        // payable(msg.sender) = payable address
        // payable(msg.sender).transfer(address(this).balance);

        // send
        // bool sendSuccess = payable(msg.sender).send(address(this).balance);
        // require(sendSuccess, "Send failed");

        // call
        (bool callSuccess, ) = i_owner.call{value: address(this).balance}("");
        require(callSuccess, "Call failed");
    }

[alymurtazamemon]

@lexorrr You do not need payable with withdraw function, people also made a PR to remove it from repo code.

[RoboCrypter]

@lexorrr : ^ Exactly!

[tamdc]

As I see Patrick doesn't use payable for withdraw function. You can check on github:
https://github.com/PatrickAlphaC/hardhat-fund-me-fcc/blob/main/contracts/FundMe.sol#L62
https://github.com/PatrickAlphaC/fund-me-fcc/blob/main/FundMe.sol#L42

For the explanation:

Functions and addresses to declared payable can receive ether into the contract.

source: https://solidity-by-example.org/payable/

[krakxn]

@lexorrr

payable is redundant for the withdraw() function and can be omitted.

payable, essentially, is used to receive Ether, which would be redundant in this case.

To this end, payable would be appropriate for a typical fund() function which the contract will use to receive Ether.

E.g. you would have noticed the use of payable when using transfer(), send() and call() (as well as for fallback/receive() which are used for receiving Ether).