Mega Code Archive
Unique Random Numbers
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<title>Unique Random Numbers</title>
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<script language="JavaScript">
// Unique Random Numbers
// -Picks a number of unique random numbers from an array
// (c) 2002 Premshree Pillai
// http://www.qiksearch.com
// http://premshree.resource-locator.com
// E-mail : qiksearch@rediffmail.com
function pickNums(nums, numArr)
{
if(nums>numArr.length)
{
alert('You are trying to pick more elements from the array than it has!');
return false;
}
var pickArr=new Array();
var tempArr=numArr;
for(var i=0; i<nums; i++)
{
pickArr[pickArr.length]=tempArr[Math.round((tempArr.length-1)*Math.random())];
var temp=pickArr[pickArr.length-1];
for(var j=0; j<tempArr.length; j++)
{
if(tempArr[j]==temp)
{
tempArr[j]=null;
var tempArr2=new Array();
for(var k=0; k<tempArr.length; k++)
if(tempArr[k]!=null)
tempArr2[tempArr2.length]=tempArr[k];
tempArr=tempArr2;
break;
}
}
}
return pickArr;
}
</script>
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<center><span class="head">Unique Random Numbers</span></center>
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This JavaScript picks up a number of unique random elements from an array.
<br><br>For example; if you have an array <font face="courier">myArray</font> consisting of 10 elements and want to pick 5 unique random elements. Suppose initially <font face="courier">myArray[3]</font> is picked randomly, then <font face="courier">myArray[3]</font> should not be picked again.
<br><br>If you want to pick 4 numbers, call the function like this : <br><font face="courier">pickNums(4,myArray)</font>. This function will return an array consisting of 4 unique random numbers. Thus you can store this array like this :<br><font face="courier">var anotherArray=pickNums(4,myArray)</font>.<br>You can now use this array for displaying the elements in different formats.
<br><br>Could be useful :-)
<br><br>Here's an example :
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<script language="JavaScript">
/* Add elements to this array */
var myArr = new Array("1","2","3","4","5","6","7","8","9");
var outArr=pickNums(5, myArr); /* Store the output */
/* Print Output */
/* Modify this part to suit your output needs */
document.write('<span style="background:#FFFFFF; border:#000000 solid 1px; padding:2px">');
for(var i=0; i<outArr.length; i++)
{
document.write('<b>' + outArr[i] + '</b> ');
}
document.write('</span>');
</script>
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<br><br><a href="javascript:void(location.reload())" class="link">Reload</a> the page to see a set of another unique random numbers.
<hr color="#808080">
© 2002 <a href="http://www.qiksearch.com" class="link">Premshree Pillai</a>.
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