added ERC20

[BChainbuddy]

Changes

Added a new ERC20 token which follows the ERC20 token standard. Also added Readme.md, which leads a user to remix to try and experiment with the contract.

FUNCTIONS AND EVENTS

I closely followed token standard and implemented all needed functionalities.

Token standard

• [x] function name() public view returns (string)

  function name() public view returns (string memory) {
      return _name;
  }

• [x] function symbol() public view returns (string)

  function symbol() public view returns (string memory) {
      return _symbol;
  }

• [x] function decimals() public view returns (uint8)

  function decimals() public view returns (uint8) {
      return 18;
  }

• [x] function totalSupply() public view returns (uint256)

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

• [x] function balanceOf(address _owner) public view returns (uint256 balance)

  function balanceOf(address _owner) public view returns (uint256) {
      return tokenBalance[_owner];
  }

• [x] function transfer(address _to, uint256 _value) public returns (bool success)

  function transfer(address to, uint256 amount) public returns (bool) {
      require(to != address(0), "Address not available");
      require(tokenBalance[msg.sender] >= amount, "Balance not high enough");
      tokenBalance[msg.sender] -= amount;
      tokenBalance[to] += amount;
      emit Transfer(msg.sender, to, amount);
      return true;
  }

• [x] function transferFrom(address _from, address _to, uint256 _value) public returns (bool success)

  function transferFrom(
      address from,
      address to,
      uint256 amount
  ) public returns (bool) {
      require(to != address(0), "Address not available");
      require(allowances[from][to] >= amount, "Allowance not high enough");
      require(tokenBalance[from] >= amount, "Balance not high enough");
      tokenBalance[from] -= amount;
      tokenBalance[to] += amount;
      allowances[from][to] -= amount;
      emit Transfer(from, to, amount);
      return true;
  }

• [x] function approve(address _spender, uint256 _value) public returns (bool success)

  function approve(address _address, uint256 amount) public returns (bool) {
      require(_address != address(0), "Address not available");
      allowances[msg.sender][_address] = amount;
      emit Approval(msg.sender, _address, amount);
      return true;
  }

• [x] function allowance(address _owner, address _spender) public view returns (uint256 remaining)

  function allowance(
      address _owner,
      address _spender
  ) public view returns (uint256) {
      return allowances[_owner][_spender];
  }

• [x] event Transfer(address indexed _from, address indexed _to, uint256 _value)

  event Transfer(
      address indexed from,
      address indexed to,
      uint256 tokenAmount
  );

• [x] event Approval(address indexed _owner, address indexed _spender, uint256 _value)

  event Approval(
      address indexed _owner,
      address indexed _spender,
      uint256 _value
  );

Non-standard token functionalities

These two functionalities need to be included due to their high importance.

Mint function

    function mint(address to, uint256 amount) public onlyOwner {
        _totalSupply += amount;
        tokenBalance[to] += amount;
        emit Mint(to, amount);
    }

Burn function

    function burn(uint256 amount) public {
        require(tokenBalance[msg.sender] >= amount, "Balance not high enough");
        tokenBalance[msg.sender] -= amount;
        _totalSupply -= amount;
        tokenBalance[address(0)] += amount;
    }

[bansaltushar014]

Reviewed!