简易计算
<br> function jiSuan(){<br> var num1 = document.getElementById("num1").value*1;<br> var num2 = document.getElementById("num2").value*1;<br> var oper = document.getElementById("oper").value;<br> res = 0<br> if(oper == "+"){<br> res = num1 + num2<br> }else if(oper == "-"){<br> res = num1 - num2<br> }else if(oper == "*"){<br> res = num1 * num2<br> }else if(oper == "/"){<br> res = num1 / num2<br> }else if(oper == "%"){<br> res = num1 % num2<br> }else{<br> res = "不能识别"<br> } <br> document.getElementById("res").value = res</p> <pre><code> } </script> </head> <body> <input id="num1" type="text"/> <input id="oper" type="text"/> <input id="num2" type="text"/> <input type="button" value="=" onclick="jiSuan()"/> <input id="res" type="text"/> </body> </code></pre> <p></html><br> 不知道哪里错了 谁能告诉我</p>