wdy.sol

pragma solidity ^0.8.2;

contract wdy {
    mapping (address => uint256) public balances;
    mapping (address => mapping(address => uint256)) public allowance;
    uint256 public totalSupply = 1000000000 * 10 ** 18;  // 1 Billion tokens with 18 bits 
    string public name = "Wednesday";
    string public symbol = "WDY";
    uint256 public decimals = 18;
   
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

    constructor(){
        balances[msg.sender] = totalSupply;
    }
   
    function balanceOf(address owner) public view returns(uint256) {
        return balances[owner];
    }
   
    function transfer(address to, uint256 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, uint256 value) public returns (bool){
        require (balanceOf(from) >= value, 'insufficient balance');
        require (allowance[from][msg.sender] >= value, 'allowance too low');
        balances[to] += value;
        balances[from] -= value;
        emit Transfer(from, to, value);
        return true;
    }
   
    function approve(address spender, uint256 value) public returns (bool) {
        allowance[msg.sender][spender] = value;
        emit Approval(msg.sender,spender,value);
        return true;
    }
}