网页计算器 – 飞-超

<!doctype html>
 <html lang="en">
 <head>
        <meta charset="UTF-8">
        <title>javascript 的calc</title>
 </head>
 <body> <center >
        <form action="" id=’meform’>
                        <input type="text" name=’num1’><br>
               
                        <input type="button" value="-" onclick="do1(’-’)">
                        <input type="button" value="+" onclick="do1(’+’)">
                        <input type="button" value="*" onclick="do1(’*’)">
                        <input type="button" value="/" onclick="do1(’/’)"><br>
                        <input type="text" name=’num2’>
                        <br>计算的结果是：<h2 id="we"></h2>
        </form></center>
         <script>
                        function do1(oper){
                        var num1 = parseFloat(document.getElementById(’meform’).num1.value)
                        var num2 =parseFloat(document.getElementById(’meform’).num2.value)
                        switch(oper){
                                case ’+’:
                                        var res=num1+num2;
                                break;
                                case ’-’:
                                        var res=num1-num2;
                                break;
                                case ’*’:
                                        var res=num1*num2;
                                break;
                                case ’/’:
                                        var res=num1/num2;
                                break;
                        }
                        document.getElementById(’we’).innerHTML = res;
                }
        </script>
 </body>
 </html>

源码演示：

javascript 的calc