General Thread for practicing question formatting!

[Khanhbroo]

    function fund() public
    {
        require(msg.value.getConversionRate() >= MINIMUM_USD, "Didn't send enough!");
        funders.push(msg.sender);
        addressToAmountFunded[msg.sender] += msg.value;
    }

On this function, I'm running into an error:

TypeError: "msg.value" and "callvalue()" can only be used in payable public functions. Make the function "payable" or use an internal function to avoid this error.
  --> contracts/FundMe.sol:31:17:
   |
31 |         require(msg.value.getConversionRate() >= MINIMUM_USD, "Didn't send enough!");
   |                 ^^^^^^^^^

Can someone tell me what's going on?

[wasim007choudhary]

function fund() public payable {
require(getConversionRate(msg.value) >= MINIMUM_USD, "Didn't send enough!");
funders.push(msg.sender);
addressToAmountFunded[msg.sender] += msg.value;
} * check this one **
payable modifier is required for any function that receives Ether. It signals that the function can handle funds sent to it during the transaction.
Without payable the function treats Ether sent to it as an error and cannot access msg.value.

In Solidity, msg.value is a uint256 (amount of Ether sent in Wei). It doesn't have a method like getConversionRate().
getConversionRate must be a standalone function or part of a contract/library. You should call it explicitly with msg.value as an argument, like getConversionRate(msg.value).

hope it helped.