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<!DOCTYPE html>
<html lang='en'><head><meta http-equiv='content-type' content='text/html; charset=UTF-8' /></head><body>
<div class="entry-content">
<div class="entry-title roundTop">
<h1 class="jq-clearfix">jQuery.each()</h1>
<div class="entry-meta jq-clearfix">
Categories:
<span class="category"><a href="http://api.jquery.com/category/utilities/" title="View all posts in Utilities">Utilities</a></span>
</div>
</div>
<div id="jQuery-each1" class="entry method">
<h2 class="jq-clearfix roundTop section-title">
<span class="name">jQuery.each( collection, callback(indexInArray, valueOfElement) )</span> <span class="returns">Returns: <a class="return" href="http://api.jquery.com/Types/#Object">Object</a></span>
</h2>
<div class="jq-box roundBottom entry-details">
<p class="desc"><strong>Description: </strong>A generic iterator function, which can be used to seamlessly iterate over both objects and arrays. Arrays and array-like objects with a length property (such as a function's arguments object) are iterated by numeric index, from 0 to length-1. Other objects are iterated via their named properties.</p>
<ul class="signatures"><li class="signature" id="jQuery-each-collection-callbackindexInArray- valueOfElement">
<h4 class="name">
<span class="versionAdded">version added: <a href="/category/version/1.0/">1.0</a></span>jQuery.each( collection, callback(indexInArray, valueOfElement) )</h4>
<p class="arguement"><strong>collection</strong>The object or array to iterate over.</p>
<p class="arguement"><strong>callback(indexInArray, valueOfElement)</strong>The function that will be executed on every object.</p>
</li></ul>
<div class="longdesc">
<p>The <code>$.each()</code> function is not the same as <a href="/each/">$(selector).each()</a>, which is used to iterate, exclusively, over a jQuery object. The <code>$.each()</code> function can be used to iterate over any collection, whether it is a map (JavaScript object) or an array. In the case of an array, the callback is passed an array index and a corresponding array value each time. (The value can also be accessed through the <code>this</code> keyword, but Javascript will always wrap the <code>this</code> value as an <code>Object</code> even if it is a simple string or number value.) The method returns its first argument, the object that was iterated.</p>
<pre>$.each([52, 97], function(index, value) {
alert(index + ': ' + value);
});
</pre>
<p>This produces two messages:</p>
<p>
<span class="output">0: 52</span><br><span class="output">1: 97</span>
</p>
<p>If a map is used as the collection, the callback is passed a key-value pair each time:</p>
<pre>var map = {
'flammable': 'inflammable',
'duh': 'no duh'
};
$.each(map, function(key, value) {
alert(key + ': ' + value);
});</pre>
<p>Once again, this produces two messages:</p>
<p>
<span class="output">flammable: inflammable</span><br><span class="output">duh: no duh</span>
</p>
<p>We can break the <code>$.each()</code> loop at a particular iteration by making the callback function return <code>false</code>. Returning <em>non-false</em> is the same as a <code>continue</code> statement in a for loop; it will skip immediately to the next iteration.</p>
</div>
<h3>Examples:</h3>
<div class="entry-examples" id="entry-examples">
<div id="example-0">
<h4>Example: <span class="desc">Iterates through the array displaying each number as both a word and numeral</span>
</h4>
<pre class="prettyprint"><code class="example demo-code"><!DOCTYPE html>
<html>
<head>
<style>
div { color:blue; }
div#five { color:red; }
</style>
<script src="http://code.jquery.com/jquery-1.7rc2.js"></script>
</head>
<body>
<div id="one"></div>
<div id="two"></div>
<div id="three"></div>
<div id="four"></div>
<div id="five"></div>
<script>
var arr = [ "one", "two", "three", "four", "five" ];
var obj = { one:1, two:2, three:3, four:4, five:5 };
jQuery.each(arr, function() {
$("#" + this).text("Mine is " + this + ".");
return (this != "three"); // will stop running after "three"
});
jQuery.each(obj, function(i, val) {
$("#" + i).append(document.createTextNode(" - " + val));
});
</script>
</body>
</html></code></pre>
<h4>Demo:</h4>
<div class="demo code-demo"></div>
</div>
<div id="example-1">
<h4>Example: <span class="desc">Iterates over items in an array, accessing both the current item and its index.</span>
</h4>
<pre class="prettyprint"><code class="example">$.each( ['a','b','c'], function(i, l){
alert( "Index #" + i + ": " + l );
});</code></pre>
</div>
<div id="example-2">
<h4>Example: <span class="desc">Iterates over the properties in an object, accessing both the current item and its key.</span>
</h4>
<pre class="prettyprint"><code class="example">$.each( { name: "John", lang: "JS" }, function(k, v){
alert( "Key: " + k + ", Value: " + v );
});</code></pre>
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