js怎么判断div下是否存在a标签如:
<div class="tabcontent" id="sc2">
<a href="#">About Us</a>
<a href="#">What do we do?</a>
<a href="#">Meet The Team</a>
<a href="#">Why work with us?</a>
</div>
<div class="tabcontent" id="sc2">
<a href="#">About Us</a>
<a href="#">What do we do?</a>
<a href="#">Meet The Team</a>
<a href="#">Why work with us?</a>
</div>
<script>
window.onload=function(){
var obj = document.getElementById("sc2");
var a = obj.getElementsByTagName("a");
if(a.length>0) alert("有a");
else alert("无a");
}
</script>
<div class="tabcontent" id="sc2">
<a href="#">About Us </a>
<a href="#">What do we do? </a>
<a href="#">Meet The Team </a>
<a href="#">Why work with us? </a>
</div>
var obj = document.getElementById("sc2");
var havea = obj.getElementsByTagName("a");
if(havea.length>0)
alert("有a元素");
else
alert("无a元素");
var obj,array;
obj=document.getElementById("sc2");
array=obj.getElementsByTagName("a");
if(array.length>0){
alert("存在a!");}
else{alert("不存在a!");}
}
用什么事件触发这个函数自己随意,onmouseover,onmousedown,window.onload,onmousemove都可以!
window.onload = function() {
var count = 0;
var div = document.getElementById("div1");
var len = div.childNodes.length;
for (var i = 0; i < len; i++) {
if (div.childNodes[i].nodeName.toLowerCase() == "a") {
count++;
}
}
alert("div1中存在"+count+"个<a>");
}
window.onload=function(){var obj= document.getElementById("sc2");var a= obj.getElementsByTagName("a");if(a.length>0) alert("有a");else alert("无a");
} </script> <divclass="tabcontent" id¡