<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT=""><script type="text/javascript">
function ok(){
alert("11111");
alert(document.getElementById("in"));
}ok();
</script>
</HEAD> <BODY>
<div id="banner">123</div>
<input type="text" value="123" id="in" />
</BODY>
</HTML>
郁闷死了,求达人解答下~
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT=""><script type="text/javascript">
function ok(){
alert("11111");
alert(document.getElementById("in"));
}ok();
</script>
</HEAD> <BODY>
<div id="banner">123</div>
<input type="text" value="123" id="in" />
</BODY>
</HTML>
郁闷死了,求达人解答下~
function ok(){
alert("11111");
alert(document.getElementById("in"));
}ok();
</script>
代码放在页面最后,你这样子调用的时候,input元素还没出来呢!
function ok(){
alert("11111");
alert(document.getElementById("in"));
}ok();
</script>
放在<input>之后DOM是顺序加载, 在加载到script标签时, <input>并没有加载到DOM中来, 所以找不到
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT=""><script type="text/javascript">
function ok(){
alert("11111");
alert(document.getElementById("in"));
}
</script>
</HEAD> <BODY onload="ok()">
<div id="banner">123</div>
<input type="text" value="123" id="in" />
</BODY>
</HTML>
你可以将执行脚本放在</body>代码之后,或者,在window.onload后再执行。
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT=""><script type="text/javascript">
function ok(){
alert("11111");
alert(document.getElementById("in").value);
}window.onload=function(){
ok()
}
</script> </HEAD> <BODY>
<div id="banner">123</div>
<input type="text" value="123" id="in" />
</BODY>
</HTML>
在<script type="text/javascript" defer></script>
</body>
<script type="text/javascript" src="banner.js"></script></html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT=""><script type="text/javascript">
function ok(){
alert("11111");
alert(document.getElementById("in"));
}window.onload=ok;
</script>
</HEAD> <BODY>
<div id="banner">123</div>
<input type="text" value="123" id="in" />
</BODY>
</HTML>