/^\d+(\.\d\d)?$/example:
<script language="javascript">
var re = /^\d+(\.\d\d)?$/
alert("0:"+re.test("0"));
alert("0.11:"+re.test("0.11"));
alert("0.113:"+re.test("0.113"));
</script>
<script language="javascript">
var re = /^\d+(\.\d\d)?$/
alert("0:"+re.test("0"));
alert("0.11:"+re.test("0.11"));
alert("0.113:"+re.test("0.113"));
</script>
<script type="text/javascript">
var CSHOW = function (f) {
//测试函数
var a = [], b = arguments, i = 1;
for (; i < b.length ; i ++) a[i - 1] = b[i] + " = " + f(b[i]);
alert(a.join("\n"));
};var isNumber = function (string) {
/*
return /^(?:\d+)?\.?\d{1,2}$/.test(string); //小数点前可以为空
*/
return /^-?(?:\d+\.?)?\d{1,2}$/.test(string);
};CSHOW(
isNumber, "123", "23.", "123.23", ".23", "1.234", "1.23"
);
</script>