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2010-05-26T08:24:50Z

1 версия

в 18:52, 25 мая 2010

2010-05-25T18:52:56Z

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== Get variable type==



<source lang="javascript">
<html>
<head>
<title>A Simple Page</title>
<script language="JavaScript">

</script>
</head>
<body>
</body>
</html></source>

== The Typeof Operator==

<p>The typeof operator takes one parameter: the variable or value to check.</p>



<source lang="javascript">
var sTemp = "test string";
alert(typeof sTemp);
alert(typeof 95);</source>

<p>Calling typeof on a variable or value returns one of the following values:</p>
<OL><LI>"undefined" if the variable is of the Undefined type.</LI><LI>"boolean" if the variable is of the Boolean type.</LI><LI>"number" if the variable is of the Number type.</LI><LI>"string" if the variable is of the String type.</LI><LI>"object" if the variable is of a reference type or of the Null type.</LI></OL>

== typeof==

<p>Syntax</p>



<source lang="javascript">
typeof(variable)</source>

== typeof a variable: number==



<source lang="javascript">
<html>
<head>
<title>Debug Example</title>
<script type="text/javascript">
function aFunction(iNum1) {
if (typeof iNum1 == "number" ){
alert("number");
}
if ( typeof iNum1 == "string") {
alert("string");
}
}
aFunction("a");
aFunction(1);
</script>
</head>
<body>
</body>
</html></source>

== typeof a variable: string==



<source lang="javascript">
<html>
<head>
<title>Debug Example</title>
<script type="text/javascript">
function aFunction(iNum1) {
if (typeof iNum1 == "number" ){
alert("number");
}
if ( typeof iNum1 == "string") {
alert("string");
}
}
aFunction("a");
aFunction(1);
</script>
</head>
<body>
</body>
</html></source>

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Admin: 1 версия

в 18:52, 25 мая 2010