1 <html> 2 <head> 3 <title>简易计算器（二）</title> 4 <script type="text/javascript"> 5 function doCal(){ 6 var value1 = parseInt(document.getElementById("value1").value); 7 var value2 = parseInt(document.getElementById("value2").value); 8 var flag = document.getElementById("flag").value; 9 var s = 0; 10 eval("s=value1"+flag+"value2"); 11 document.getElementById("span1").innerHTML ="<font color='red'>" +s+"</font>"; 12 alert(s); 13 } 14 </script> 15 </head> 16 <body> 17 <input type="text" id="value1"> 18 <select id="flag"> 19 <option>+</option> 20 <option>-</option> 21 <option>*</option> 22 <option>/</option> 23 </select> 24 <input type="text" id="value2"> 25 <input type="button" id="=" value="=" onClick="doCal()"> 26 <span id="span1"></span> 27 </body> 28 </html>
收获：获取值然后要转换为int型的，eval的使用