[Misiur]

pawn Код:

stock in_array(array[], value, size = sizeof array)
{
    for(new i; i < size; i++)
    {
        if(array[i] == value) return 1;
    }
    return 0;
}

Why? Because sizeof is resolved at compile time, not run time. You have to pass the size when you call the function. You might be interested with custom iterators from y_iterate/foreach. But that's for bigger dynamic arrays. Also, you could simply return index at the same time, with -1 when not found.