php array_push() -> How not to push if the array already contains the value

maybe you want to use it as an associative array instead. it's implemented as (something like) a hash table, so you get constant insert time instead of linear.

function find_uniq( $something ) {
    foreach($something as $value){
         $liste[$value]++;
    }
    return array_keys( $liste );
}

Two options really.

Option 1: Check for each item and don't push if the item is there. Basically what you're asking for:

foreach($something as $value) {
    if( !in_array($value,$liste)) array_push($liste,$value);
}

Option 2: Add them anyway and strip duplicates after:

foreach($something as $value) {
    array_push($liste,$value);
}
$liste = array_unique($liste);

By the look of it though, you may just be looking for $liste = array_unique($something);.

You can simply check this condition before calling array_push(). Use array_search() and use a strong comparison to false to see if the value is present:

foreach( $something as $value ){
    if( array_search( $value, $liste, true ) === false ){
        array_push( $liste, $value );
    }
}

(By the way: Add ,true to array_search to use "strict checking". This will use === for comparisons instead of ==)

Great answers are already present above, but if you have multiple array_push() all over your code, it would be a pain to write if(in_array()) statements every time.

Here's a solution that will shorten your code for that case: Use a separate function.

function arr_inserter($arr,$add){ //to prevent duplicate when inserting
    if(!in_array($add,$arr))
        array_push($arr,$add);
    return $arr;
}

Then in all your array_push() needs, you can call that function above, like this:

$liste = array();
foreach($something as $value){
    $liste = arr_inserter($liste, $value);
}

If $value is already present, $liste remains untouched.

If $value is not yet present, it is added to $liste.

Hope that helps.