<script type="text/javascript"> function fun(t){ var fa = parseInt(document.getElementById('fa').value); var fb = parseInt(document.getElementById('fb').value); var fc = document.getElementById('fc'); if(isNaN(fa) || isNaN(fb)){ alert("输入错误，请重新输入"); return; } switch(t){ case 1: fc.value = fa + fb; break; case 2: fc.value = fa - fb; break; case 3: fc.value = fa * fb; break; case 4: fc.value = fa / fb; break; } } </script> </head> <body> <input type="text" id="fa" value=""/> <input type="text" id="fb" value=""/> <input type="text" id="fc" value=""/> <input type="button" value="+" onclick="fun(1);" /> <input type="button" value="-" onclick="fun(2);" /> <input type="button" value="x" onclick="fun(3);" /> <input type="button" value="/" onclick="fun(4);" />
HTML 计算器
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>计算器</title> </head> <script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script> <script type="text/javascript"> $(function(){ $("button").click(function(){ var first = parseInt($("#first").val());//获取第一个数的值并转化为数字 var second = parseInt($("#second").val());//获取第二个数的值并转化为数字 var sum = 0;//定义结果值 var symbol = parseInt($("[type=radio]:checked").val());//获取符号的值 //通过对符号的判断计算结果 switch(symbol){ case 0: sum = first + second; break; case 1: sum = first - second; break; case 2: sum = first * second; break; case 3: sum = first / second; break; } var arr = ['+','-','*','/'];//输出的符号 $("h2 span").text(first + arr[symbol] + second +" = " +sum);//把结果输出到结果栏中 }) }) </script> <body> <h1>计算器</h1> <p>数字一：<input type="text" id="first" style=" 40px;" /></p> <p> <label><input type="radio" name="symbol" value="0" checked="checked"/>+</label> <label><input type="radio" name="symbol" value="1" />-</label> <label><input type="radio" name="symbol" value="2" />*</label> <label><input type="radio" name="symbol" value="3" />/</label> </p> <p>数字二：<input type="text" id="second" style=" 40px;" /></p> <p><button>计算</button></p> <h2>结果：<span></span></h2> </body> </html>