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  1. PO
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    <p>you have a few issues there: </p> <ul> <li><p>variables in the global window scope </p></li> <li><p>an array declared with the <code>new</code> keyword instead of a literal </p></li> <li><p>trying to use variables before declaring them</p></li> <li><p>jQuery.inArray being incorrectly used (<a href="http://api.jquery.com/jQuery.inArray/" rel="nofollow">inArray returns a number</a>, not <code>true</code> or <code>false</code>)</p></li> <li><p>inefficient code with a <code>while</code> loop which theoretically could lead to an infinite loop</p></li> </ul> <p>now, the second combined with the third is the main issue here, as the first time you test for <code>x</code> in the array it is <code>undefined</code> (you are only defining it inside the <code>if</code> with a <code>var</code> statement, so the x is at first undefined) and thus it matches the first element in the array (which is <code>undefined</code> as you declared <code>r</code> with <code>new Array(6)</code>) and the inArray function returns 1, which leads to an infinite loop.</p> <p>There are several things you could do to patch that code, but I think a complete rewrite with a different approach might be better and requires no jQuery at all.</p> <p>This modified version of your code should work fine:</p> <pre><code>var Show = 6, // Number of logos to show TotalLogos = 21, // Total number of logos to choose from FirstPart = '&lt;img src="/wp-content/client-logos/logo', LastPart = '.jpg" height="60" width="120" /&gt;', array = [], // array with all avaiilable numbers rnd, value, i, logosElement = document.getElementById('client-logos'); for (i = 0; i &lt; TotalLogos; i++) { // arrays are zero based, for 21 elements you want to go from index 0 to 20. array[i] = i + 1; } for (i = 0; i &lt; Show; i++) { // pick numbers rnd = Math.floor(Math.random() * array.length); value = array.splice(rnd,1)[0]; // remove the selected number from the array and get it in another variable logosElement.innerHTML += (FirstPart + value + LastPart); } </code></pre> <p><br></p> <p>To explain a little what I did here:</p> <ul> <li><p>initialize an array with all the possible values you have (numbers 1 to 21)</p></li> <li><p>run a loop only as many times as numbers you want to pick.</p></li> <li><p>generate a random number from 0 to the maximum index available in your numbers array</p></li> <li><p>remove the number at that index from the array using splice, and then use it to create the string for the innerHTML call (<a href="https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/splice" rel="nofollow">splice returns the elements removed from the array as another new array</a>).</p></li> <li><p>additionally, the <code>logosElement</code> variable is cached at the beginning so you only do a single DOM lookup for the element.</p></li> </ul> <p>There are more ways that code can be rewritten and even cleaned up, but I figured this would be the cleanest way to help you with your issue (and it's cross-browser safe! no need to add jQuery unless you need it for another functionality)</p>
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    1. POHow to choose a set of unique random numbers (no duplicates) using the jQuery.inArray method?
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    1. POHow to choose a set of unique random numbers (no duplicates) using the jQuery.inArray method?
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    1. COWow! Works perfectly and you explained it extremely well. Thank you a thousand times.
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      1. USShaun Scovil
 

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