php: check if an array has duplicates

Question

I\'m sure this is an extremely obvious question, and that there\'s a function that does exactly this, but I can\'t seem to find it. In PHP, I\'d like to know if my array has

Answer 1

The simple solution but quite faster.

$elements = array_merge(range(1,10000000),[1]);

function unique_val_inArray($arr) {
    $count = count($arr);
    foreach ($arr as $i_1 => $value) {
        for($i_2 = $i_1 + 1; $i_2 < $count; $i_2++) {
            if($arr[$i_2] === $arr[$i_1]){
                return false;
            }
        }
    }
    return true;
}

$time = microtime(true);
unique_val_inArray($elements);
echo 'This solution: ', (microtime(true) - $time), 's', PHP_EOL;

Speed - [0.71]!