jsp中的简易计算器怎么判断输入的是不是数字

JavaScript021

jsp中的简易计算器怎么判断输入的是不是数字,第1张

无语，一个计算器也需要用JSP来做？还要什么JRE环境，多此一举！

JS就直接搞定啦！

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<input type="text" name="currentPage1" id="swords"

onkeyup="this.value=this.value.replace(/[^\d\.\+]/g,'')" />

这样就OK啦。用JS正则表达式限制用户只能输入数字就OK了。你复制粘贴用一下试试。如果你也不允许他输入小数点，那你就把代码中的（\.）去掉，不允许输入加号，就去掉（\+）

这个。。简单点jsp+servlet 就行了，jsp把页面显示出来，点击计算后，把数据传给后台的servlet，处理完数据后把结果再显示到原JSP页面上。

LZ是要思路？ 还是没接触过JSP与servlet

<html>

<head>

<meta http-equiv="Content-Type" content="text/htmlcharset=gb2312">

<title>网页特效|网页特效代码(JsHtml.cn)---普通计算器代码</title>

</head>

<body>

<script language="JavaScript">

<!-- Hide the script from old browsers --

function compute(obj)

{obj.expr.value = eval(obj.expr.value)}

var one = '1'

var two = '2'

var three = '3'

var four = '4'

var five = '5'

var six = '6'

var seven = '7'

var eight = '8'

var nine = '9'

var zero = '0'

var plus = '+'

var minus = '-'

var multiply = '*'

var divide = '/'

var decimal = '.'

function enter(obj, string)

{obj.expr.value += string}

function clear(obj)

{obj.expr.value = ''}

// --End Hiding Here -->

</script>

<form name="calc">

<table border=1>

<td colspan=4><input type="text" name="expr" size=30 action="compute(this.form)"><tr>

<td><input type="button" value=" 7 " onClick="enter(this.form, seven)">

<td><input type="button" value=" 8 " onClick="enter(this.form, eight)">

<td><input type="button" value=" 9 " onClick="enter(this.form, nine)">

<td><input type="button" value=" / " onClick="enter(this.form, divide)">

<tr><td><input type="button" value=" 4 " onClick="enter(this.form, four)">

<td><input type="button" value=" 5 " onClick="enter(this.form, five)">

<td><input type="button" value=" 6 " onClick="enter(this.form, six)">

<td><input type="button" value=" * " onClick="enter(this.form, multiply)">

<tr><td><input type="button" value=" 1 " onClick="enter(this.form, one)">

<td><input type="button" value=" 2 " onClick="enter(this.form, two)">

<td><input type="button" value=" 3 " onClick="enter(this.form, three)">

<td><input type="button" value=" - " onClick="enter(this.form, minus)">

<tr><td colspan=2><input type="button" value=" 0 " onClick="enter(this.form, zero)">

<td><input type="button" value=" . " onClick="enter(this.form, decimal)">

<td><input type="button" value=" + " onClick="enter(this.form, plus)">

<tr><td colspan=2><input type="button" value=" = " onClick="compute(this.form)">

<td colspan=2><input type="button" value="AC" size= 3 onClick="clear(this.form)"></table>

</form>

</body>

</html>

执行的结果如下图: