1. 很多时候，input只关心最后状态，不需要用useState
   
2. 有时候并不需要用useEffect去改变值
   
3. useMemo防止object在重新渲染时再内部值不变时被更换内存地址，变成新“值”
   
4. 适时终止过时的api请求
   

https://www.npmjs.com/package/bignumber.js

import BigNumber from "bignumber.js"
console.log( new BigNumber('123456789.7654321').toFormat(2) )

输出：123,456,789.77

1. Add custom.d.ts to ./scr

   declare module '*.svg' {
     import React = require('react')
     export const ReactComponent: React.FC<React.SVGProps<SVGSVGElement>>
     const src: string
     export default src
   }

2. Import svg on your page

   import { ReactComponent as IconLogo } from '../assets/images/logo.svg'

3. Usage

   <IconLogo height='10' />