Dynamically check for strings in a PHP array

Question

EDIT: ten months later, I'm still back to this.. still can't figure it out :(

I can search for a string in an array no problem; this works:

if (in_array('animals', $value[tags])){
   echo "yes";
}

But how can I check for a variable in the array? This doesn't seem to work:

$page_tag = 'animals';
if (in_array($page_tag, $value[tags])){
   echo "yes";
}

I'm guessing I'm missing some simple syntax doodad?

The array is massive, so I'll try and show a sample of it. It is stored on a separate php file and "included" in other places.

global $GAMES_REPOSITORY;
$GAMES_REPOSITORY = array   (
     "Kitten Maker"      => array   (
        "num"   => "161",
        "alt"   => "Kitten Maker animal game",
        "title" => "Create the kitten or cub of your dreams!",
        "tags"  => array ("animals", "feline", "cats", "mega hits"),
     ),
}

Here's a larger part of the code, to put into context. It pulls from the array of ~400 games, and pulls the ones with a specific tag:

function array_subset($arr) {
    $newArray = array();
    foreach($arr as $key => $value) {
        if (in_array($page_tag, $value["tags"])){
            if(is_array($value)) $newArray[$key] = array_copy($value);
            else if(is_object($value)) $newArray[$key] = clone $value;
            else $newArray[$key] = $value;
        }
    }
    return $newArray;
}
function array_copy($arr) {
    $newArray = array();
    foreach($arr as $key => $value) {
        if(is_array($value)) $newArray[$key] = array_copy($value);
        else if(is_object($value)) $newArray[$key] = clone $value;
        else $newArray[$key] = $value;
    }
    return $newArray;
}
$games_list = array();
$games_list = array_subset($GAMES_REPOSITORY);
$games_list = array_reverse($games_list);

Oh, an interesting hint. Elsewhere it DOES work using $_GET:

if (in_array($_GET[tagged], $value[tags])){

show your array

Vision Coderz
– Vision Coderz

2017-10-03 18:05:12 +00:00
Commented Oct 3, 2017 at 18:05 — Vision Coderz
– Vision Coderz, Commented Oct 3, 2017 at 18:05
@iCoders I added a piece of the array to the question

ola.rogula
– ola.rogula

2017-10-03 18:29:32 +00:00
Commented Oct 3, 2017 at 18:29 — ola.rogula
– ola.rogula, Commented Oct 3, 2017 at 18:29

Brian Quirion · Accepted Answer · 2017-10-03 18:23:59Z

1

The in_array() function can check variables, so it is likely that your problem comes from somewhere else. Verify that you've defined your constant tags correctly. If it's not defined, it might not work depending on your PHP version. Some versions just assume that you wanted to write the string tags instead of a constant named tags.

Your code works. Here's a full example that I've tested that works well:

<?php
const tags = "tags";
$page_tag = 'animals';
$value = array('tags' => array("fruits", "animals"));

if (in_array($page_tag, $value[tags])){
   echo "yes";
}

answered Oct 3, 2017 at 18:23

Brian Quirion

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8 Comments

ola.rogula Over a year ago

Thanks @Brian I added a piece of the array to the question. Okay, good to know that the code works. I'm trying to figure out how to incorporate your answer...

Brian Quirion Over a year ago

Have you tried writing $value["tags"] instead of $value[tags] ?

ola.rogula Over a year ago

Trying now. No, didn't work. I assumed that part wasn't the problem because in_array('animals', $value[tags]) does work...?

Brian Quirion Over a year ago

Well, your syntax is correct. So, it's likely that the problem comes from somewhere else. Maybe try it that way without the constants... if (in_array($page_tag, $GAMES_REPOSITORY["Kitten Maker"]["tags"]))

ola.rogula Over a year ago

Thank you. I can't quite word it like that because it's nested in a loop, in a function. But I think that's basically what it's doing now. I've added more of the code... maybe I've messed something up further up the function :/

|

RockwoodON · Accepted Answer · 2017-10-03 19:10:23Z

1

You have an array of arrays, so in_array() wont work as you have written it as that test for existence in an array, not a subarray. You may as well just loop through your arrays like this:

foreach($GAMES_REPOSITORY as $name =>$info) {
   if(in_array($page_tag, $info['tags']))
   {  whatever  } 
}

If that is not fast enough you will have to cache your tags by looping ahead of time and creating an index of tags.

answered Oct 3, 2017 at 19:10

RockwoodON

1493 bronze badges

1 Comment

ola.rogula Over a year ago

Isn't that what I'm doing though? I can't see significant differences between your code and mine.. (i appended more of the code near the bottom of the question later)

ola.rogula · Accepted Answer · 2018-08-10 18:57:22Z

I finally got it to work! I don't entirely understand why, but I had to feed the variable into the function directly. For some reason it wouldn't pull the variable from the parent function. But now it works and it even takes two dynamic variables:

function array_subset2($arr, $tag1, $tag2) {
    $newArray = array();
    foreach($arr as $key => $value) {
        if (in_array($tag1, $value['tags'])){
            if (in_array($tag2, $value['tags'])){
                if(is_array($value)) $newArray[$key] = array_copy2($value);
                else if(is_object($value)) $newArray[$key] = clone $value;
                else $newArray[$key] = $value;
            }
        }
    }
    return $newArray;
}
function array_copy2($arr) {
    $newArray = array();
    foreach($arr as $key => $value) {
        if(is_array($value)) $newArray[$key] = array_copy2($value);
        else if(is_object($value)) $newArray[$key] = clone $value;
        else $newArray[$key] = $value;
    }
    return $newArray;
}
$games_list = array();
$games_list = array_subset2($GAMES_REPOSITORY, $page_tag, $featured_secondary_tag);

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