6-11编程练习
新手求6-11计算器的答案
qq_onewayforwar_0
2017-08-14
2 回答
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var a = '';
//获取第一个输入框的值
var txt1 = parseInt(document.getElementById("txt1").value);
//获取第二个输入框的值
var txt2 = parseInt(document.getElementById("txt2").value);
//获取选择框的值
var select = document.getElementById("select").value;
switch(select){
case "+":
a = txt1 + txt2;
break;
case "-":
a = txt1 - txt2;
break;
case "*":
a = txt1 * txt2;
break;
case "/":
a = txt1 / txt2;
}
//设置结果输入框的值
document.getElementById("fruit").value = a;
}
</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()"/>
<input type='text' id='fruit' />
</html>
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var txt1=Number(document.getElementById("txt1").value);
var txt2=Number(document.getElementById("txt2").value);
var sel=document.getElementById("select").value;
var sum;
if(sel=="+"){
sum=txt1+txt2;
}else if(sel=="-"){
sum=txt1-txt2;
}else if(sel=="*"){
sum=txt1*txt2;
}else if(sel=="/"){
sum=txt1/txt2;
}
document.getElementById("fruit").value=sum;
}
</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>
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