How to rewrite this php filterArray function for better performance

Question

I have a filterArray method in a class which I use for filtering out an array based on another:

function filterArray($needle, $heystack, $always = array())
{
    foreach($heystack as $k => $v)
    {
        if( !in_array($v, $needle) && !in_array($v, $always) )
            unset($heystack[$k]);
    }

    return $heystack;
}

Usage:

$chars  = array('l', 'J', 'F');
$keys   = array('d','D','j','l','N','S','w','z','W','F','m','M','n','t','L','o','Y','y','a','A','c','r','e','T');
$keys   = filterArray($chars, $keys, array('z'));

note that $always is an array of items that should always be present and should not be filtered out. The result of key is:

$keys   = array('l', 'J', 'F', 'z');

This is more of a validation process. Is there a better way to write this and optimize it for performace? because it's used in a class where performance is crucial.

Thank you.

in_array is slow, use a linked-list

DevZer0
– DevZer0

2013-09-02 12:48:37 +00:00
Commented Sep 2, 2013 at 12:48 — DevZer0
– DevZer0, Commented Sep 2, 2013 at 12:48
@DevZer0 That's PHP >= 5.3 my code requires 5.2+

Sallar
– Sallar

2013-09-02 13:17:40 +00:00
Commented Sep 2, 2013 at 13:17 — Sallar
– Sallar, Commented Sep 2, 2013 at 13:17

DevZer0 · Accepted Answer · 2013-09-02 13:02:25Z

2

you didn't specify if there is a need to maintain key association, if key association is not required you can do the following function.

function filterArray($needle, $heystack, $always = array())
{
    return array_intersect(array_merge($needle, $always), $heystack);
}

answered Sep 2, 2013 at 13:02

DevZer0

13.5k7 gold badges29 silver badges54 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Sallar Over a year ago

Thanks, this is the one. It's much faster. Executed in 0.000007 Seconds on my machine while the old version was executed in 0.0001 second

Dan Power · Accepted Answer · 2013-09-02 12:59:04Z

0

This should do the trick.

function filterArray($needle, $heystack, $always = array()) {

    $merged = array_merge($needle, $always);

    return array_intersect($heystack, $merged);
}

answered Sep 2, 2013 at 12:59

Dan Power

1,1411 gold badge12 silver badges18 bronze badges

Collectives™ on Stack Overflow

How to rewrite this php filterArray function for better performance

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related