Im getting this error message from this particular piece of code - solidity

Question

interface IERC20 {
function totalSupply() external view returns (uint256);
function balanceOf(address who) external view returns (uint256);
function allowance(address owner, address spender) external view returns (uint256);
function transfer(address to, uint256 value) external returns (bool);
function approve(address spender, uint256 value) external returns (bool);
function transferFrom(address from, address to, uint256 value) external returns (bool);
}
And along with this error i am recieving this error message
This contract may be abstract, not implement an abstract parent's methods completely or not invoke an inherited contract's constructor correctly.
what can i do to work around this?

Answer 1

You are trying to deploy an interface, which is not possible because it doesn't contain any code - just definition of functions.
If you already have a contract that implements this interface, you need to select it in the "Deploy" tab, see the screnshot:
If you haven't implemented the contract, you're in the very beginning and need to implement the whole thing to have a working ERC-20 token contract.
There is no "best way" to create an ERC-20 token, because each contract can be implemented differently but still implement the ERC-20 standard. For starters, I'd recommend reading the OpenZeppelin docs and their source codes to see how they implement the standard. Or if you google "minimal erc-20 contract", you'll find few more implementations that might be easier to grasp.
pragma solidity ^0.8;
interface IERC20 {
function totalSupply() external view returns (uint256);
function balanceOf(address who) external view returns (uint256);
function allowance(address owner, address spender) external view returns (uint256);
function transfer(address to, uint256 value) external returns (bool);
function approve(address spender, uint256 value) external returns (bool);
function transferFrom(address from, address to, uint256 value) external returns (bool);
}
contract MyContract is IERC20 {
function totalSupply() external view returns (uint256) {
// TODO implement this function
}
function balanceOf(address who) external view returns (uint256) {
// TODO implement this function
}
// TODO implement all functions of the interface
}