array_unique?

No as far as the function doesn’t ‘remember’ previous values.
I need to generate 50 squares with different background colors and different size…
The function is called in a cycle and it contains numbers itself so finally everything is repeated 3-5 times!

What a sophistication 

shuffle. And not in cycle, of course. Once is enough.

PilgrimFarAway, where have you found ‘15000 massive values each of which contains 100 symbols’ mentioned?

where have you found ‘15000 massive values each of which contains 100 symbols’ mentioned?

Really, it wasn’t mentioned…
Generally shuffle is convenient to use. But you are not to exceed memory_limit.

P.S. I haven’t tested it yet but it’s possible that function rand(x,y); will also display ‘repeating’ values.

<?php
$input = array("a" => "green", "red", "b" => "green", "blue", "red");
$result = array_unique($input);
print_r($result);
?>