JSFiddle - React, Tailwind, and code Playground

by Shang-De You

HTML

<div id="element-id">
  aaa
</div>

JavaScript

let addBorder = () => {
debugger
	console.log(this)
  //this.style.border = '1px solid red'
  // 點擊el調用addBorder，this會指向el，因此el會加上紅線
}

var el = document.querySelector('#element-id')

el.addEventListener('click', addBorder)