test

[MoveLikeRabbit]

   function fund() public {
        require(msg.value > MINIMUM_USD, "Didn't send enough!"); // 1e18 == 1* 10**18 = 10000000000000000000
        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.

Can someone tell me what's going on ?

[HarigovindM-G]

Hey Mate ,
You are Encountering the error because you are using msg.value in a non payable function , just make the function payable to solve your issue , ie function fund() public payable {...}

[tal7aouy]

The error you're encountering is because the msg.value property, which indicates the amount of Ether sent with a transaction, can only be accessed in functions that are marked as payable. The payable keyword indicates that the function can receive Ether.

Here's how you can fix your function by marking it as payable:

function fund() public payable {
    require(msg.value > MINIMUM_USD, "Didn't send enough!"); // 1e18 == 1* 10**18 = 10000000000000000000
    funders.push(msg.sender);
    addressToAmountFunded[msg.sender] = msg.value;
}

By adding the payable keyword, you're allowing the fund function to receive Ether, and thus msg.value will be a valid property.

Explanation

• payable keyword: This keyword allows the function to accept Ether.
• msg.value: This property holds the amount of Wei (smallest denomination of Ether) sent with the transaction. It can only be accessed in payable functions.

Without the payable keyword, the function cannot handle Ether transfers, which is why you're encountering the error. Adding payable ensures the function can accept and work with the Ether sent to it.