Someone Can Help Me With This Warning Error! It Stuck My code

Question

I'm trying to create an ERC20 token and if someone sends ether to this contract, contract will send equivalent tokens to the calling address.

Code:::

pragma solidity ^0.6.6;

import "./new1ERC20.sol";

  contract ConfigureERC20 is new1ERC20 {

     uint256 tokenPrice = 500000000000000 wei;
     uint256 public tokensToGet = 0;

     fallback() external payable {
        require(msg.value > 0);
     //   require(tokensRemaining > 0);
        tokensToGet = msg.value / tokenPrice;

        //_balances[] = balances[fundsWallet] - amount;
        //_balances[msg.sender] = _balances[msg.sender].add(balance);
        emit Transfer(address(this), msg.sender, tokensToGet);
        msg.sender.transfer(tokensToGet);
    }
}

Thanks!

Answer 1

As @goodvibration mentioned you have failed to post the essential parts of the code.

Anyway, based on the error message you are most likely using the pre-0.6 style of defining a single fallback function like this:

function() payable external { } (https://solidity.readthedocs.io/en/v0.5.3/contracts.html#fallback-function)

In Solidity version 0.6 the way of defining fallback functions was changed. There are now two separate functions: receive and fallback and their signature have changed - they are incompatible with pre-0.6 versions. So the function signatures are:

fallback() external { } and

receive() external payable { }

https://solidity.readthedocs.io/en/v0.6.0/contracts.html#receive-ether-function

If you use Solidity version 0.6 or greater you can't use the old-style single fallback function anymore. So upgrade your code to conform to the new style and you should be ok.