How Do I Add A checkBalance Function To This ERC20 Smart Contract - ethereum

Question

I Need To Know The Balance Of This Token After I Deploy It In Remix Ethereum Firefox. I Want To Know Where Do I Add The checkBalance Function. Plz Help Guys. This Is My First ERC20 Smart Contract.
pragma solidity ^0.5.0;
contract TusharCoin {
uint256 public totalSupply;
string public name;
string public symbol;
uint32 public decimals;
address public owner;
mapping(address => uint256 ) balances;
event Transfer(address to, uint256 amount);
constructor () public {
symbol = "TUSHAR";
name = "TusharCoin";
decimals = 5;
totalSupply = 100000000000;
owner = msg.sender;
balances[msg.sender] = totalSupply;
emit Transfer(msg.sender, totalSupply);
}
}

Answer 1

Your token currently isn't an ERC20 token as it doesn't fully implement the ERC20 standard yet.
To just add a balanceOf function to your existing contract you can add the following:
function balanceOf(address account) public view returns (uint256) {
return balances[account];
}
If you are creating your own ERC20 implementation then you should consider using SafeMath, see the documentation for details: https://docs.openzeppelin.com/contracts/2.x/utilities#math
If you are creating ERC20 tokens you may want to look at the OpenZeppelin Contracts implementation to see if this meets your needs. See the documentation for details: https://docs.openzeppelin.com/contracts/2.x/tokens#ERC20
An example ERC20 Token that you can deploy with Remix inheriting from the OpenZeppelin Contracts implementation is below using your specified name, symbol, decimals and totalSupply:
pragma solidity ^0.5.0;
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v2.3.0/contracts/token/ERC20/ERC20.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v2.3.0/contracts/token/ERC20/ERC20Detailed.sol";
contract Token is ERC20, ERC20Detailed {
constructor () public ERC20Detailed("Tushar Token", "TUSHAR", 5) {
_mint(msg.sender, 1000000 * (10 ** uint256(decimals())));
}
}
If you have questions on using OpenZeppelin you can ask in the Community Forum: https://forum.openzeppelin.com/
Disclosure: I am the Community Manager at OpenZeppelin

Answer 2

Below, I have mention checkBalance function. In ERC20 standards checkBalance function to be stated as a balanceOf function.
In function, view means one can only read not write
function balanceOf(address accountAddress) public view returns (uint256) {
return balances[accountAddress];
}
Full source code.
pragma solidity ^0.5.0;
contract TusharCoin {
uint256 public totalSupply;
string public name;
string public symbol;
uint32 public decimals;
address public owner;
mapping(address => uint256 ) balances;
event Transfer(address to, uint256 amount);
constructor () public {
symbol = "TUSHAR";
name = "TusharCoin";
decimals = 5;
totalSupply = 100000000000;
owner = msg.sender;
balances[msg.sender] = totalSupply;
emit Transfer(msg.sender, totalSupply);
}
function balanceOf(address accountAddress) public view returns (uint256) {
return balances[accountAddress];
}
}
If you want whole code for ERC20. Let me know.