current community

your communities

more stack exchange communities

company blog
Stack Exchange Inbox Reputation and Badges
tour help
Code Review Stack Exchange is a question and answer site for peer programmer code reviews. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top
up vote 2 down vote favorite

I want to see if one of two values (a, b) are in an array. Here's my current thought:

$match_array = array('a','b');
$array_under_test = array('b', 'd', 'f');

if (array_intersect($match_array, $array_under_test)) {
  // Success!
}

Any better implementations?

share|improve this question
up vote 2 down vote accepted

If you want to verify that either value is in the $array_under_test, array_intersect may not be the best option. It will continue to test for collisions even after it finds a match.

For two search strings you can just do:

if (in_array('a', $array_under_test) || in_array('b', $array_under_test)) {
  // Success!
}

This will stop searching if 'a' is found in the $array_under_test.

For more than two values, you can use a loop:

foreach ($match_array as $value) {
  if (in_array($value, $array_under_test)) {
    // Success!
    break;
  }
}
share|improve this answer
up vote 1 down vote

In addition to p.w.s.g's answer (which seems fine):

If you have lots of values you need to find, you can use a hash: 

// the values go into keys of the array
$needles = array('value1' => 1, 'value2' => 1, 'value3' => 1);
$haystack = array('test', 'value1', 'etc');

// only go through the array once
$found = false;
foreach($haystack as $data) {
   if (isset($needles[$data])) {
       $found = true; break;
   }
 }

It's worth doing this if you search $haystack a lot of times.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.