<!DOCTYPE html><html> <head> <title> 事件</title> <script type="text/javascript"> function count(){ var Txt1=document.getElementById("txt1"); var Txt2=document.getElementById("txt2"); var Select=document.getElementById("select"); var result; switch(Select) { case "+": result=parseInt(Txt1.value)+parseInt(Txt2.value); break; case "-"; result=parseInt(Txt1.value)-parseInt(Txt2.value); break; case "*": result=parseInt(Txt1.value)*parseInt(Txt2.value); break; default: result=parseInt(Txt1.value)/parseInt(Txt2.value); break; } document.getElementById("fruit").value=result; } </script> </head> <body> <input type='text' id='txt1' /> <select id='select'> <option value="+">+</option> <option value="-">-</option> <option value="*">*</option> <option value="/">/</option> </select> <input type='text' id='txt2' /> <input type='button' value=' = ' onclick="count()" /> <!--通过 = 按钮来调用创建的函数，得到结果--> <input type='text' id='fruit' /> </body></html>
3 回答
李晓健
TA贡献1036条经验 获得超461个赞
function count(){
var Txt1=document.getElementById("txt1");
var Txt2=document.getElementById("txt2");
var Select=document.getElementById("select");
var result;
//这里要取值
switch(Select.value)
{ case "+":
result=parseInt(Txt1.value)+parseInt(Txt2.value);
break;
//这里是 : 不是 ;
case "-":
result=parseInt(Txt1.value)-parseInt(Txt2.value);
break;
case "*":
result=parseInt(Txt1.value)*parseInt(Txt2.value);
break;
default:
result=parseInt(Txt1.value)/parseInt(Txt2.value);
break;
}
document.getElementById("fruit").value=result;
}看注释
李晓健
TA贡献1036条经验 获得超461个赞
function count(){
var Txt1=document.getElementById("txt1");
var Txt2=document.getElementById("txt2");
var Select=document.getElementById("select");
var result;
//这里要取值
switch(Select.value)
{ case "+":
result=parseInt(Txt1.value)+parseInt(Txt2.value);
break;
//这里是 : 不是 ;
case "-":
result=parseInt(Txt1.value)-parseInt(Txt2.value);
break;
case "*":
result=parseInt(Txt1.value)*parseInt(Txt2.value);
break;
default:
result=parseInt(Txt1.value)/parseInt(Txt2.value);
break;
}
document.getElementById("fruit").value=result;
}看注释
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