L@_@K
<!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="">
</HEAD> <BODY>
<input id="txtNum" />
<input type="button" onclick="isNum()" />
<script type="text/javascript"> function isNum(){
var s = document.getElementById("txtNum").value;
var reg = /^(0?|\d+)$/;
if(reg.test(s))
alert("OK");
else
alert("NO");
}
</script> </BODY>
</HTML>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
</HEAD> <BODY>
<input id="txtNum" />
<input type="button" onclick="isNum()" />
<script type="text/javascript"> function isNum(){
var s = document.getElementById("txtNum").value;
var reg = /^(0?|\d+)$/;
if(reg.test(s))
alert("OK");
else
alert("NO");
}
</script> </BODY>
</HTML>
<input type="button" onclick="isNum()" />
<script type="text/javascript">function isNum(){
var s = document.getElementById("txtNum").value;
var reg = /^0$/;
var reg2 = /^[1-9]\d*$/;
if(reg.test(s) || reg2.test(s)){
alert("OK");
return;
}
alert("NO")
}
</script>我这样写是正确的,我现在的疑惑是,为什么我用“|”把reg 和reg2 合成 var reg = /^(0)|([1-9]\d*)$/; ,它就错误了呢???