window.onload = function(){
var container = document.getElementById("container");
var btn = container.getElementsByTagName("input");
var box = container.getElementsByTagName("div");
for(var i = 0; i < btn.length; i ++){
btn[i].onclick = function(){
for(var i = 0; i < btn.length; i ++)
{
btn[i].className = "none";
}
this.className = "btclass";
}
}
}
<style>
#container div{width:200px; height:200px; border:1px solid black; background:gray; display:none;}
.btclass{background:yellow;}
</style>
<body>
<div id="container">
<input class="btclass" type="button" value="出国">
<input type="button" value="留学">
<input type="button" value="旅游">
<input type="button" value="读书">
<div style="display:block">第一个</div>
<div>第二个</div>
<div>第三个</div>
<div>第四个</div>
</div>
</body>
JS里面这个btn[i].className = "none";为什么要又要写在一个循环里面去执行,不能跟this.className = "btclass"并立吗?
this...后面没i,况且你你合并了就不能循环了,循环就是要在for的大括号里面对吗?!!明白吗?