（一）原生js遍历
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script src="js/jquery.min.js" type="text/javascript" charset="utf-8"></script>
</head>
<body>
<span class="a">微信</span>
<span class="a">QQ</span>
<span class="a">微博</span>
<span class="a">短信</span>
<button id="btn">点击我触发</button>
</body>
<script type="text/javascript">
var btn = document.getElementById("btn");
btn.onclick = function(){
var arr = document.getElementsByClassName("a");
for(var i=0;i<arr.length;i++){
console.log("获取到的结果是："+arr[i].innerText)
}
}
</script>
</html>（二）jquery的each循环遍历
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script src="js/jquery.min.js" type="text/javascript" charset="utf-8"></script>
</head>
<body>
<span class="a">微信</span>
<span class="a">QQ</span>
<span class="a">微博</span>
<span class="a">短信</span>
<button id="btn">点击我触发</button>
</body>
<script type="text/javascript">
$("#btn").on("click",function(){
$(".a").each(function(){
console.log($(this).text());
})
})
</script>
</html>（三）jquery的for循环遍历
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script src="js/jquery.min.js" type="text/javascript" charset="utf-8"></script>
</head>
<body>
<span class="a">微信</span>
<span class="a">QQ</span>
<span class="a">微博</span>
<span class="a">短信</span>
<button id="btn">点击我触发</button>
</body>
<script type="text/javascript">
$("#btn").on("click",function(){
var span = $(".a");
for(var i=0;i<span.length;i++){
console.log($(".a").eq(i).text());
}
});
</script>
</html>