摸一哈
2020-03-10 14:25
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var one=document.getElementById("txt1").value; one=parseInt(one);
var two=document.getElementById("txt2").value;
twe=parseInt(twe);
var a=doucument.getElementById("select").value;
var num;
switch(a){
case "+":
num=one+two;
break;
case "-":
num=one-two;
break;
case "*":
num=one*two;
break;
case "/" :
num=one/two;
break;
}
document.getElementById("fruit").value=num;
} </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>
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var txt1=document.getElementById("txt1").value;
var txt2=document.getElementById("txt2").value;
var select=document.getElementById("select").value;
//获取第一个输入框的值
//获取第二个输入框的值
//获取选择框的值
//获取通过下拉框来选择的值来改变加减乘除的运算法则
//设置结果输入框的值
var sum;
switch(select){
case"+":
sum=parseInt(txt1)+parseInt(txt2);
break;
case'-':
sum=parseInt(txt1)-parseInt(txt2);
break;
case'*':
sum=parseInt(txt1)*parseInt(txt2);
break;
case'/':
sum=parseInt(txt1)/parseInt(txt2);
break;
}
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>
<!DOCTYPE html>
改成这样:
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var one=document.getElementById("txt1").value; one=parseInt(one);
var two=document.getElementById("txt2").value;
two=parseInt(twe);
var a=document.getElementById("select").value;
var num;
switch(a){
case "+":
num=one+two;
break;
case "-":
num=one-two;
break;
case "*":
num=one*two;
break;
case "/" :
num=one/two;
break;
}
document.getElementById("fruit").value=num;
} </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>
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count() {
var one = parseInt( document.getElementById("txt1").value);
var two = parseInt( document.getElementById("txt2").value);
var a = document.getElementById("select").value;
var num;
switch (a) {
case "+":
num = one + two;
break;
case "-":
num = one - two;
break;
case "*":
num = one * two;
break;
case "/":
num = one / two;
break;
}
document.getElementById("fruit").value = num;
}
</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>
var two=document.getElementById("txt2").value;
twe=parseInt(twe);
上面一句的 twe = parseInt(twe)改成 var two = parseInt(two)
var a=doucument.getElementById("select").value; //这一句的document 拼写错了
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