<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>Title</title></head><body><button>按钮</button><button>按钮</button><button>按钮</button><button>按钮</button><button>按钮</button><button>按钮</button><script>var btns = document.getElementsByTagName('button');for (var i = 0; i < btns.length; i++) {btns[i].onclick=function () {console.log(i);for (var j=0;j<btns.length;++j){btns[j].style.backgroundColor='';}this.style.backgroundColor='pink';}}</script></body></html>
