My Token

// SPDX-License-Identifier: UNLICENSED

pragma solidity ^0.8.8;

contract Token {
    mapping(address => uint) public balances;
    mapping(address => mapping(address => uint)) public allowance;
    uint public totalSupply = 1000000 * 10 ** 18;
    string public name = "My Token";
    string public symbol = "MTN";
    uint public decimals = 18;

    event Transfer(
        address indexed from,
        address indexed to,
        uint value
    );

    event Approval(
        address indexed owner,
        address indexed spender,
        uint value
    );

    constructor() {
        balances[msg.sender] = totalSupply;
    }

    function balanceOf(address owner) public view returns(uint) {
        return balances[owner];
    }

    function transfer(address to, uint value) public returns(bool) {
        require( balanceOf(msg.sender) >= value , "insufficient balance");
        balances[to] += value;
        balances[msg.sender] -= value;
        emit Transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) public returns(bool) {
        require( balanceOf(from) >= value, 'Insufficient balance');
        require(allowance[from][msg.sender] >= value, 'allownace too low');
        balances[to] += value;
        balances[from] -= value;
        emit Transfer(from, to, value);
        return true;

    }

    function approve(address spender, uint value) public returns(bool) {
        allowance[msg.sender][spender] = value;
        emit Approval(msg.sender, spender, value);
        return true;
    }


}