Q:

50 random unique elements from an array of 1000 elemens?

What is the simplest way to get 50 random unique elements from an array of 1000 elements ?
text = new Array();
for(i=0;i<1000;i++){ text[i]=i; }   //array populated
// now I need to get 50 random unique elements from this array.

A:

The obvious (to me) way is to shuffle the array, then take the first fifty elements.  This question has a good way to shuffle an array, and you can then slice the first fifty elements. This guarantees the elements will be unique.
So, using the function there:
fisherYates(text);
text = text.slice(0, 50);

