Php get value from array

Question

Array
(
[0] => stdClass Object
    (
        [product_id] => 12
        [cat_id] => 1
     )
[1] => stdClass Object
    (
        [product_id] => 23
        [cat_id] => 3
     )
[2] => stdClass Object
    (
        [product_id] => 44
        [cat_id] => 1
     )
)

How can I get only objects with [cat_id]=1 ?

[array_filter](http://www.php.net/manual/en/function.array-filter.php) — Blazemonger, May 29 '13 at 15:43

score 1 · Answer 1 · answered May 29 '13 at 15:49

1

try this:

$result = array_filter($objects, function($a){ return ($a->cat_id === 1); });

or for PHP < 5.3:

function my_filter($a){ return ($a->cat_id === 1); }
$result = array_filter($objects, 'my_filter');

$result should then contain the items you are looking for.

answered May 29 '13 at 15:49

StampyCode

7,218
3
28
44

I wonder what the performance difference is between using `array_filter` with a callback function as opposed to manually iterating the array with PHP's interpreted `foreach`. Would be interesting to see. – crush May 29 '13 at 15:50
built in functions are usually more efficient that loops, and `for(;;)` is usually more efficient that `foreach()` – StampyCode May 29 '13 at 15:52
Yes, but the built in `array_filter` still has to call an interpreted function. – crush May 29 '13 at 15:53
It's an anonymous function, not an interpreted one. It isn't compiled in userland, it's still precompiled, so shouldn't have significant drawbacks. – StampyCode May 29 '13 at 15:56
Your `my_filter()` function isn't compiled in userland? (even the anonymous form in 5.3+) That's news to me. – crush May 29 '13 at 15:57
http://stackoverflow.com/questions/8676888/anonymous-function-performance-in-php - actually that doesn't help. – StampyCode May 29 '13 at 15:59
Interesting read. thanks. – crush May 29 '13 at 16:01

crush · Answer 2 · 2013-05-29T15:49:36.870

0

Let $yourArray be equal to the array in your question.

$objects = array();

foreach ($yourArray as $entry) {
    if ($entry->cat_id === 1)
        $objects[] = $entry;
}

$objects would then hold the items with cat_id equal to 1.

Or, with array_filter() function:

function getCategory1Elements($value) {
    return $value->cat_id === 1;
}

$yourArray = array_filter($yourArray, "getCategory1Elements");

edited May 29 '13 at 15:49

answered May 29 '13 at 15:42

crush

16,713
9
59
100

score 0 · Answer 3 · answered May 29 '13 at 15:46

$data = Array ( [0] => stdClass Object ( [product_id] => 12 [cat_id] => 1 ) [1] => stdClass Object ( [product_id] => 23 [cat_id] => 3 ) [2] => stdClass Object ( [product_id] => 44 [cat_id] => 1 ) );

$copy = $data;
foreach ($data as $key => $val) {
    if ($val->cat_id != 1) unset($copy[$key])
}

Once you're done, $copy will only contain object with a cat_id of 1. This method will preserve array keys.

Php get value from array

3 Answers3