<script language="网页特效">
function isnumber(str){
if(""==str){
return false;
}
var reg = /d/;
return str.match(reg)==null;
}
</script>
<script language="javascript">
function check()
{
if(form1.good_name.value=="")
{
alert("请填写货品名称！");
form1.good_name.focus();
return false;
}if(form1.number1.value=="")
{alert("请填写货品数量！");
form1.number1.focus();
return false;}
if(!isnum(form1.number1.value)){
alert("请输入数字!")
form1.number1.focus();
return false;
}
}function isnum(num){
var renum=/^d*$/;
return(renum.test(num));
}
</script>上面看了二款判断是否为数字的函数，下面来看看一款完整的验证是否为数字的实例吧。
<!doctype html public "-//w3c//dtd html 4.01//en" "http://www.111cn.net/tr/html4/strict.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=gb2312" />
<title>js判断是否为数字函数</title>
</head>
<body>
<input type="text" id="myinput" value="" />
<input type="button" value="确定" id="mybutton" />
</body>
</html>
<script language="javascript" type="text/javascript">
function $(obj){
return document.getelementbyid(obj);
}
function checkisinteger(str)
{
//如果为空，则通过校验
if(str == "")
return true;
if(/^(-?)(d+)$/.test(str))
return true;
else
return false;
}
string.prototype.trim = function()
{
return this.replace(/(^[s]*)|([s]*$)/g, "");
}
$("mybutton").onclick=function(){
if(checkisinteger($("myinput").value.trim())){
alert("成功");
}else{
alert("只能是数字");
}
}
</script>