检查数组中键“孔”的简单方法

Question

I have a simple associative array:

$ar = array( 1=>'foo', 2=>'bar', 5=>'foobar', 8=>'barfoo' )

I need to efficiently find holes in the keys. The keys are guaranteed to be integers.

findHole($ar)
> 0
findHole($ar,1)
> 3

findHole($ar,5)
> 6

what is the easiest way to do this?

Answer 1

Try this:

function findHole($array, $key=0) {
    while (array_key_exists($key, $array)) {
        $key++;
    }
    return $key;
}