[英]How can use AND statement in if with javascript?
Hello everyone I'm trying to run multiple javascripts and use AND statement. 大家好我正在尝试运行多个javascripts并使用AND语句。 When user click an option which has value="1986" and click other option which has value="3", some text will appear.
当用户单击值为“1986”的选项并单击其他值为“3”的选项时,将显示一些文本。 I have used AND statement in if statement but it doesn't work.
我在if语句中使用了AND语句,但它不起作用。 Here is my code :
这是我的代码:
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js"></script></script>
<script type="text/javascript">
$(document).ready(function() {
$('#main').on('change', '.select-box', function() {
if ($(".select-box option[value='3']").attr('selected') & $(".select-box option[value='1986']").attr('selected')) {
$('#demo').html("Hello World");
}
});
});
</script>
<script type="text/javascript">
var x="",i;
for(i=1986;i<2013;i++)
{
x=x + "<option value='"+i+"'> " + i + "</option>";
}
$(document).ready(function() {
document.getElementById("demo2").innerHTML="<select class='select-box'>"+x+"</select>";
});
</script>
</head>
<body>
<p id="demo2"></p>
<div id="main">
<select class="select-box">
<option value="0">alert</option>
<option value="1">alert to</option>
<option value="2">no alert</option>
<option value="3">best alert</option>
</select>
<p><br/>
<div id="demo"></div>
</div>
</body>
You need to use &&
你需要使用
&&
if ($(".select-box option[value='3']").attr('selected') && $(".select-box option[value='1986']").attr('selected'))
________________________________________________________^
Logical operators: 逻辑运算符:
&& = and
|| = or
! = not
and you must change the select class from first select
otherwise you will not get them both. 并且您必须从第一次
select
更改选择类,否则您将不会同时获得它们。
To use the AND statement, it should be &&
. 要使用AND语句,它应该是
&&
。
So for your if statement it should be 所以对于你的if语句应该是
if ($(".select-box option[value='3']").attr('selected') && $(".select-box option[value='1986']").attr('selected')) {
$('#demo').html("Hello World");
}
第二个(外部)括号似乎也很重要。
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