How to do Random pick from array with no repeat...

[mazdaspring]

My array contains 15 value I want to random pick 5 value:

 myArray[0] ="a";
 myArray[1] ="b";
 myArray[2] ="c";
 myArray[3] ="d";
 myArray[4] ="e";
 myArray[5] ="f";
 myArray[6] ="g";
 myArray[7] ="h";
 myArray[8] ="i";
 myArray[9] ="j";
 myArray[10] ="k";
 myArray[11] ="l";
 myArray[12] ="a";
 myArray[13] ="b";
 myArray[14] ="c";

How to random pick from all elements with no repeat of the same content.
e.g. if myArray[0] is picked then myArray[12] will not be picked again. (because they have the same value "a")

[jimhill]

Originally Posted by mazdaspring

My array contains 15 value I want to random pick 5 value:

 myArray[0] ="a";
 myArray[1] ="b";
 myArray[2] ="c";
 myArray[3] ="d";
 myArray[4] ="e";
 myArray[5] ="f";
 myArray[6] ="g";
 myArray[7] ="h";
 myArray[8] ="i";
 myArray[9] ="j";
 myArray[10] ="k";
 myArray[11] ="l";
 myArray[12] ="a";
 myArray[13] ="b";
 myArray[14] ="c";

How to random pick from all elements with no repeat of the same content.
e.g. if myArray[0] is picked then myArray[12] will not be picked again. (because they have the same value "a")

If you are able to write the basic javascript, in the loop concantenate the results into a string then check the string for a repeat prior to adding a new character. Let me know if you dont understand and I will code it for you.

[rnd me]

simply shuffle the array and use [].pop() to draw one index at a from the top; you'll never repeat.

//define array:
myArray=["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "a", "b", "c"];

 //shuffle array:
myArray.sort(function(){return Math.round(Math.random());});


//show 5 picks from shuffled array:
alert( [
 myArray.pop(),
 myArray.pop(),
 myArray.pop(),
 myArray.pop(),
 myArray.pop()
]);

[Philip M]

Try this as an alternative to rnd me's neat solution:-

<script type = "text/javascript">
var myArray = []; 
 myArray[0] ="a";  // I assume these are phrases or sentences, not just letters
 myArray[1] ="b";
 myArray[2] ="c";
 myArray[3] ="d";
 myArray[4] ="e";
 myArray[5] ="f";
 myArray[6] ="g";
 myArray[7] ="h";
 myArray[8] ="i";
 myArray[9] ="j";
 myArray[10] ="k";
 myArray[11] ="l";
 myArray[12] ="a";
 myArray[13] ="b";
 myArray[14] ="c";

var len = myArray.length;
var chosen = [];

for (var i = 0; i<=4; i++) {
var randy = Math.floor(Math.random() * len);  
chosen[i] = myArray[randy];

for (k=0; k<=i-1; k++) {
if (chosen[k] == chosen[i]) {
i--;  // duplicate found so decrement i
}
}
}

alert (chosen);

</script>

Quizmaster: What is the more common name given to the aurora borealis?
Contestant: Hmm, I'm not really a plant person.

[mazdaspring]

Thank you so much. It works really well.