# Random numbers

**URL:** <https://forum.kirupa.com/t/random-numbers/16028>\
**Category:** programming\
**Created:** [March 20, 2003, 9:25am UTC](https://forum.kirupa.com/t/random-numbers/16028 "2003-03-20T09:25:07Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![zen](https://avatars.discourse-cdn.com/v4/letter/z/7c8e57/32.png) [@zen](https://forum.kirupa.com/u/zen)\
**Post date:** [March 20, 2003, 9:25am UTC](https://forum.kirupa.com/t/random-numbers/16028/1 "2003-03-20T09:25:07Z")

</div>

erm…i was just wondering how to create random numbers without ever repeating the same number twice or more

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<div class="post-metadata">

**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/kirupa/original/3X/6/2/621e5c11736f46532526e61be85940af4230f3e5.png) [@system](https://forum.kirupa.com/u/system)\
**Post date:** [March 20, 2003, 5:14pm UTC](https://forum.kirupa.com/t/random-numbers/16028/2 "2003-03-20T17:14:18Z")

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```auto

int(Math.random()*1000000000000))

```

creates an random number from 0 to 1000000000000  
1 on 1000000000000 change to get the same number…  
😃

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<div class="post-metadata">

**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/kirupa/original/3X/6/2/621e5c11736f46532526e61be85940af4230f3e5.png) [@system](https://forum.kirupa.com/u/system)\
**Post date:** [March 20, 2003, 7:17pm UTC](https://forum.kirupa.com/t/random-numbers/16028/3 "2003-03-20T19:17:49Z")

</div>

its usually done using an array. How many numbers do you need to be random?  
ex:

```auto

//create array 0-100
randNums = [];
for (i=0;i<=100;i++) randNums* = i;

// randomize at once by sort
randNums.sort(function(){return random(2)*2-1});
// then step through array for each random value

// OR

// randomize as stepping through individually
for (i=100;i>=0;i--){
     var rand = random(i), lastVal = randNums*;
     randNums* = randNums[rand];
     randNums[rand] = lastVal;
}

```

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<div class="post-metadata">

**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/kirupa/original/3X/6/2/621e5c11736f46532526e61be85940af4230f3e5.png) [@system](https://forum.kirupa.com/u/system)\
**Post date:** [March 21, 2003, 1:17am UTC](https://forum.kirupa.com/t/random-numbers/16028/4 "2003-03-21T01:17:07Z")

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oh i get it…using array then sort it out…(kind of comparing it right?) if its the same…then return another value if its not go on with the array…kind of troublesome…

```
thanks but is there an easier way like ....canceling out the numbers when it aready has been display erm...that would be assably thanks anyway
```

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<div class="post-metadata">

**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/kirupa/original/3X/6/2/621e5c11736f46532526e61be85940af4230f3e5.png) [@system](https://forum.kirupa.com/u/system)\
**Post date:** [March 21, 2003, 6:32am UTC](https://forum.kirupa.com/t/random-numbers/16028/5 "2003-03-21T06:32:20Z")

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See [this thread](http://64.207.155.38/forums/showthread.php?s=&threadid=17290)… Dealing the same stuff I guess… 😉