Finding Elements That Pass a Certain Test (PHP Cookbook)

4.14.2. Solution

Use a foreach loop:

$movies = array(...);

foreach ($movies as $movie) {
    if ($movie['box_office_gross'] < 5000000) { $flops[] = $movie; }
}

Or array_filter( ):

$movies = array(...);

function flops($movie) {
    return ($movie['box_office_gross'] < 5000000) ? 1 : 0;
}

$flops = array_filter($movies, 'flops');

4.14.3. Discussion

The foreach loops are simple; you scroll through the data and append elements to the return array that match your criteria.

If you want only the first such element, exit the loop using break :

foreach ($movies as $movie) {
    if ($movie['box_office_gross'] > 200000000) { $blockbuster = $movie; break; }
}

You can also return directly from a function:

function blockbuster($movies) {
    foreach ($movies as $movie) {
        if ($movie['box_office_gross'] > 200000000) { return $movie; }
    }
}

With array_filter( ), however, you first create a callback function that returns true for values you want to keep and false for values you don't. Using array_filter( ), you then instruct PHP to process the array as you do in the foreach.

It's impossible to bail out early from array_filter( ), so foreach provides more flexibility and is simpler to understand. Also, it's one of the few cases in which the built-in PHP function doesn't clearly outperform user-level code.

4.14. Finding Elements That Pass a Certain Test

4.14.1. Problem

4.14.2. Solution

4.14.3. Discussion

4.14.4. See Also


4.13. Finding the Position of an Element in an Array		4.15. Finding the Largest or Smallest Valued Element in an Array