Ethereum Cookbook

How to do it…

1. To create an ERC20-based token in Ethereum, you need to follow a certain standard. The contract should include the following functions:
   • totalSupply()
   • balanceOf(address _owner)
   • transfer(address _to, uint256 _value)
   • transferFrom(address _from, address _to, uint256 _value)
   • approve(address _spender, uint256 _value)
   • allowance(address _owner, address _spender)

It should also include these events:

• • transfer(address indexed _from, address indexed _to, uint256 _value)
  • approval(address indexed _owner, address indexed _spender, uint256 _value)

We will discuss each function and event in detail throughout this chapter.

2. Create a contract with the target compiler version and a name:

pragma solidity ^0.4.23;contract ERC20 {    ..