PHP Unique Random Numbers

Question

What would be a good way to generate 7 unique random numbers between 1 and 10. I can\'t have any duplicates. I could write a chunk of PHP to do this (using rand() and pushin

Answer 1

The "shuffle" method has a MAJOR FALW. When the numbers are big, shuffle 3 billion indexs will instantly CAUSE 500 error. Here comes a best solution for really big numbers.

function getRandomNumbers($min, $max, $total) {
    $temp_arr = array();
    while(sizeof($temp_arr) < $total) $temp_arr[rand($min, $max)] = true;
    return $temp_arr;
}

Say I want to get 10 unique random numbers from 1 billion to 4 billion.

$random_numbers = getRandomNumbers(1000000000,4000000000,10);

PS: Execution time: 0.027 microseconds