PHP Array: array filter with argument

Question

I have this simple array in PHP that I need to filter based on an array of tags matching those in the array.

Array
(
    [0] => stdClass Object
        (
            [name] => Introduction
            [id] => 798162f0-d779-46b6-96cb-ede246bf4f3f
            [tags] => Array
                (
                    [0] => client corp
                    [1] => version 2
                )
        )

    [1] => stdClass Object
        (
            [name] => Chapter one
            [id] => 761e1909-34b3-4733-aab6-ebef26d3fcb9
            [tags] => Array
                (
                    [0] => pro feature
                )
        )
)

When supplied with 'client corp', the output should be the above array with only the first item.

So far I have this:

$selectedTree = array_filter($tree,"checkForTags");

function checkForTags($var){

   $arr = $var->tags;
   $test = in_array("client corp", $arr, true);

   return ($test);
}

However, the result is that it's not filtering. When I echo $test, I get 1 all the time. What am I doing wrong?

Try using the array_map() function instead of the array_filter() function: php.net/array_map — RichardBernards
– RichardBernards, Commented Nov 20, 2014 at 15:52

RichardBernards · Accepted Answer · 2014-11-21 08:22:05Z

1

Something like this should do the trick:

$selectedTree = array_filter(array_map("checkForTags", $tree ,array_fill(0, count($tree), 'client corp')));

function checkForTags($var, $exclude){
   $arr = $var->tags;
   $test = in_array($exclude, $arr, true);
   return ($test ? $var : false);
}

array_map() makes sure you can pass arguments to the array. It returns each value altered. So in the returning array, some values are present, others are set to false. array_filter() with no callback filters all falsey values from that array and you are left with the desired result

edited Nov 21, 2014 at 8:22

answered Nov 20, 2014 at 15:55

RichardBernards

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6 Comments

RichardBernards Over a year ago

Sorry... small typo there... Updated the answer

greener Over a year ago

why is there both an array_filter and an array_map?

RichardBernards Over a year ago

@greener array_map() makes sure you can pass arguments to the array. It returns each value altered. So in the returning array, some values are present, others are set to false. array_filter() with no callback filters all falsey values from that array and you are left with the desired result

greener Over a year ago

Thanks for the explanation. When I replace the array values with the json payload array(Input::json("selectedTags")) it filters out everything again. Something small is missing but your answer is correct.

greener Over a year ago

Upon further testing, it looks like there are issues with this approach. If I pass pro feature as the argument, the returned array is empty when it should instead show the second item of the initial array.

|

N.DeNisse · Accepted Answer · 2014-11-20 16:06:50Z

0

The in_array() function returns TRUE if needle is found in the array and FALSE otherwise. So by getting 1 as a result that means that "client corp" is found.

Check PHP in_array() manual

You can user array_search() to return the array key instead of using in_array().

edited Nov 20, 2014 at 16:06

answered Nov 20, 2014 at 15:59

N.DeNisse

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