这段react代码为什么渲染了三次

Question

这段react代码为什么渲染了三次呢，打印出来render是有三次，不是应该两次吗？

import React  from 'react';
const Toggle = (props) => {
  const [ num ,setNumber ] = React.useState(0)
  setTimeout(() => {
    setNumber(1)
  }, 0)
  console.log('render'); // render three times ?
  return <button >{ console.log(num) } {num}</button>
};

export default Toggle;

但是一下这段代码只渲染了一次?

import React  from 'react';
const Toggle = (props) => {
  const [ num ,setNumber ] = React.useState(0)
  setTimeout(() => {
    setNumber(0) // change
  }, 0)
  console.log('render'); // render one times ?
  return <button >{ console.log(num) } {num}</button>
};

export default Toggle;