May I transfer token address to ERC20 of openzeppelin's lib

Support Contracts
1

For using openzeppelin's ERC20 one can tansfer token info by constructor.
But for token making by myself, it seems not work.
I can use something like
ERC20(token address).totalSupply();
for Public function in ERC20, but for private variables in ERC20, it does not work.
May I transfer token address to ERC20?

:1234: Code to reproduce

// SPDX-License-Identifier: no license
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";



contract MyContract is ERC20 {

    constructor() public ERC20("masaToken", "MASASET") {}
    address MyToken = 0x3114DbeAE60a6Ea05d04A8b361B261990b04606e;

    function total1() public view returns (uint256){
        return totalSupply();
    }


        function total2() public view returns (uint256){
        return ERC20(MyToken).totalSupply();
    }


    
}

:computer: Environment

Remix-IDE

2

Not sure what is the question here. I recommend using Contracts Wizard if you need guidance on writing a token.

3

I am sorry for the wrong code. The correct one is follows.
I use Remix-IDE and have made an ERC20 token "masaToken" at BSC testnet.
The token address is 0x3114DbeAE60a6Ea05d04A8b361B261990b04606e.

// SPDX-License-Identifier: no license
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract MyTokenContract is ERC20 {
    address MyToken = 0x3114DbeAE60a6Ea05d04A8b361B261990b04606e;

    constructor() ERC20("masaToken", "MASASET") {
    }


    function total1() public view returns (uint256){
        return totalSupply();
    }


    function total2() public view returns (uint256){

        return ERC20(MyToken).totalSupply();
    }    
}

When I used above code to test it, I found that the correct token info cannot
be transfered by constructor.The result of total1() is 0， but total2() is 1000000000000000000000.

4

That's because on BSC Testnet, on adress 0x3114DbeAE60a6Ea05d04A8b361B261990b04606e there really does exist a token with totalSupply 10,000 and 18 decimals. Therefore total2() is reporting correctly.

total1() is also reporting correctly because it's returning the totalSupply of MyContract, as declared in the ERC20 inheritance. Because you didn't initialize or assigned a value to totalSupply, it's reporting the default value for uint256s in solidity: 0.

Everything works as expected, you should read a bit more on what you're trying to do.

--
Telegram:
@dimisfou

1 Like
5

@dimisfou
Thank you very much.
The token MASASET with address 0x3114DbeAE60a6Ea05d04A8b361B261990b04606e
is made by myself as follows:
my account:0x70D39C39Ac97707A8028f99f49fabdb65c84ACE3
hash:0xdc14c57859b9f72683763ed5fe2efd83d84e2999e1a909e59d45567cfa974fd9

Because I am a beginer of solidity, would you like to tell me how can I
get the correct totalSupply() of the token MASASET without using
ERC20(MyToken). My purpose is to use burn() and burnfrom() functions in
ERC20.

6

What is the problem with using ERC20(MyToken)?

You can declare the variable as type ERC20 instead of address.

ERC20 MyToken = ERC20(address(0x3114DbeAE60a6Ea05d04A8b361B261990b04606e));
7

Thank you very much.
Such as the function total1(), the problem is
if I donnot use ERC20(MyToken),
I cannot get the correct the totalSupply() of the token MASASET.

I hope to not use ERC20(MyToken) to get the correct info of the token MASASET,
becasuse I hope to use burn() and burnfrom() functions in ERC20.