Mastering Blockchain Programming with Solidity

Full ERC20 implementation using ERC20.sol

We discussed the ERC20 token standard and its functions in detail in Chapter 7, ERC20 Token Standard. You can refer to that chapter for a detailed explanation. In this section, we will look into the OpenZeppelin implementation files for the ERC20 token standard.

The OpenZeppelin contract can be found at Chapter09/openzeppelin-solidity/contracts/token/ERC20/ERC20.sol. You can also refer to the full code of ERC20.sol file that's available on GitHub at https://github.com/PacktPublishing/Mastering-Solidity/blob/master/Chapter09/openzeppelin-solidity/contracts/token/ERC20/ERC20.sol.

The following code is a shortened version:

contract ERC20 is IERC20 {    using SafeMath for uint256;    mapping (address => uint256 ...