<!DOCTYPE html> <html> <head lang="en"> <meta charset="UTF-8"> <!--<meta http-equiv="content-type" content="text/html"; charset="GB2312"/>--> <title></title> <style> input { border: solid 1px black }
.cc { width: 18px } </style> </head> <body> <input type="text" id="num1"/> <input type="text" id="mum3" class="cc"/> <input type="text" id="num2"/> <input type="button" value="等于" id="btnCal"/> <input type="text" id="num3"/> </body> <script type="text/javascript"> function calSum(){ var a=parseInt(document.getElementById("num1").value); var b=parseInt(document.getElementById("num2").value); var c=String(document.getElementById("mum3").value); // switch(c){ // case"+":document.getElementById("num3").value =(a+b);break; // case"-":document.getElementById("num3").value =(a-b);break; // case"*":document.getElementById("num3").value =(a*b);break; // case"/":document.getElementById("num3").value =(a/b);break; // case"%":document.getElementById("num3").value =(a%b);break; // } if (c==="+") { document.getElementById("num3").value = (a + b); } else { if (c==="-") { document.getElementById("num3").value = (a - b); } else { document.getElementById("num3").value = (a / b); if (c==="*") { document.getElementById("num3").value = (a * b); } else { document.getElementById("num3").value = (a / b); } } }
}
//function calSum(){ // var a=parseInt(document.getElementById("num1").value); // var b=parseInt(document.getElementById("num2").value); // var c=String(document.getElementById("mum3").value); // switch (c){ // case "+":document.getElementById("num3").value= (a+b);break; // case "-":document.getElementById("num3").value=(a-b);break; // case "*":document.getElementById("num3").value=(a*b);break; // case "/":document.getElementById("num3").value= (a/b);break; // case "%" :document.getElementById("num3").value= (a%b);break; // } //} document.getElementById("btnCal").onclick=calSum; </script>
</html>原文：http://www.cnblogs.com/dugufeiyang/p/5471219.html