<!DOCTYPE html><html xmlns="http://www.w3.org/1999/html"><head lang="en"> ???<meta charset="UTF-8"> ???<title></title> ???<script> ???????function add(){ ???????????var a=parseInt(document.getElementById("num1").value);/*获取a的值*/ ???????????var b=parseInt(document.getElementById("num2").value); ???????????var c=parseInt(document.getElementById("num3").value=a+b);/*value=a+b 将a+b的值传给num3*/ ??????????// alert(a+b); ???????} ???????function de(){ ???????????var a=parseInt(document.getElementById("num1").value)/*获取a的值*/ ???????????var b=parseInt(document.getElementById("num2").value); ???????????var c=parseInt(document.getElementById("num3").value=a-b); ??????????// alert(a-b); ???????} ???????function mul(){ ???????????/*放在方法里，点击才开始访问数据*/ ???????????var a=parseInt(document.getElementById("num1").value);/*获取a的值*/ ???????????var b=parseInt(document.getElementById("num2").value); ???????????var c=parseInt(document.getElementById("num3").value=a*b); ???????????//alert(a*b); ???????} ???????function chu(){ ???????????var a=parseInt(document.getElementById("num1").value);/*获取a的值*/ ???????????var b=parseInt(document.getElementById("num2").value); ???????????var c=parseInt(document.getElementById("num3").value=a/b); ??????????// alert(a/b); ???????} ???</script></head><br> ???<label>简易计算器</label></br> ???<label>第一个数：</label><input type="=text" id="num1"></br> ???<label>第二个数：</label><input type="=text" id="num2"></br> ???<button onclick="add()">+</button> ???<button onclick="de()">-</button> ???<button onclick="mul()">*</button> ???<button onclick="chu()">/</button><br> ???<label>结果：</label><input type="text" id="num3"></body></html><!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/html">
<head lang="en">
???<meta charset="UTF-8">
???<title></title>
???<script>
???????function add(){
???????????var a=parseInt(document.getElementById("num1").value);/*获取a的值*/
var b=parseInt(document.getElementById("num2").value);
???????????var c=parseInt(document.getElementById("num3").value=a+b);/*value=a+b 将a+b的值传给num3*/
alert(a+b);
???????}
???????function de(){
???????????var a=parseInt(document.getElementById("num1").value)/*获取a的值*/
var b=parseInt(document.getElementById("num2").value);
???????????var c=parseInt(document.getElementById("num3").value=a-b);
???????????alert(a-b);
???????}
???????function mul(){ ???????????/*放在方法里，点击才开始访问数据*/
var a=parseInt(document.getElementById("num1").value);/*获取a的值*/
var b=parseInt(document.getElementById("num2").value);
???????????var c=parseInt(document.getElementById("num3").value=a*b);
???????????alert(a*b);
???????}
???????function chu(){
???????????var a=parseInt(document.getElementById("num1").value);/*获取a的值*/
var b=parseInt(document.getElementById("num2").value);
???????????var c=parseInt(document.getElementById("num3").value=a/b);
???????????alert(a/b);
???????}
???</script>
</head>
<br>
???<label>简易计算器</label></br>
???<label>第一个数：</label><input type="=text" id="num1"></br>
???<label>第二个数：</label><input type="=text" id="num2"></br>
???<button onclick="add()">+</button>
???<button onclick="de()">-</button>
???<button onclick="mul()">*</button>
???<button onclick="chu()">/</button><br>
???<label>结果：</label><input type="text" id="num3">
</body>
</html>
JS编写简易计算器
原文地址：http://www.cnblogs.com/Andy-/p/7586771.html