Question

我在javascript中有一个简单的switch case示例。但是，段落中的值应该反映为switch-case中的第三个选项，它没有显示任何内容或空白段落。 Pl，求助！

＆＃13;

<html>
<head></head>
<body>
<p id="para1"></p>
<script>
var i = 3; 
switch(i){
case 1: {
	document.getElementById('para1').value = "The value is one.";
	break;
}
case 2: {
	document.getElementById('para1').value = "The value is two.";
	break;
}
case 3: {
	document.getElementById('para1').value = "The value is three.";
	break;
}
default:{
	document.getElementById('para1').value = "The value is undefined."
}
}
</script> 
</body>
</html>

＆＃13;

Answer 1

select top 1 ed.*, e.salary form Emp e INNER JOIN EmpDetail ed ON e.ID=ed.ID WHERE ed.City='Nagpur' order by e.Salary desc标记在p元素中，因此它没有input。您应该使用value来设置值。

innerHTML

Answer 2

使用innerHTML而不是value：

<html>
<head></head>
<body>
<p id="para1"></p>
<script>
var i = 3; 
switch(i){
case 1: {
	document.getElementById('para1').innerHTML = "The value is one.";
	break;
}
case 2: {
	document.getElementById('para1').innerHTML = "The value is two.";
	break;
}
case 3: {
	document.getElementById('para1').innerHTML = "The value is three.";
	break;
}
default:{
	document.getElementById('para1').innerHTML = "The value is undefined."
}
}
</script> 
</body>
</html>

Answer 3

＆＃13;

var i = 3; 
switch(i){
case 1: {
	document.getElementById('para1').innerHTML = "The value is one.";
	break;
}
case 2: {
	document.getElementById('para1').innerHTML = "The value is two.";
	break;
}
case 3: {
	document.getElementById('para1').innerHTML = "The value is three.";
	break;
}
default:{
	document.getElementById('para1').innerHTML = "The value is undefined."
}
}

＆＃13;

<p id="para1">test</p>

＆＃13;

切换案例简单示例不反映段落中的值

3 个答案: