Search for values in nested array [duplicate]

Question

This question already has answers here:

How to check if a specific value exists at a specific key in any subarray of a multidimensional array? (19 answers)

Closed 1 year ago.

I have an array as follows

array(2) {
 ["operator"] => array(2) {
 ["qty"] => int(2)
 ["id"] => int(251)
 }
 ["accessory209"] => array(2) {
 ["qty"] => int(1)
 ["id"] => int(209)
 }
 ["accessory211"] => array(2) {
 ["qty"] => int(1)
 ["id"] => int(211)
 }
}

I'm trying to find a way to verify an id value exists within the array and return bool. I'm trying to figure out a quick way that doesn't require creating a loop. Using the in_array function did not work, and I also read that it is quite slow.

In the php manual someone recommended using flip_array() and then isset(), but I can't get it to work for a 2-d array.

doing something like

if($array['accessory']['id'] == 211)

would also work for me, but I need to match all keys containing accessory -- not sure how to do that

Anyways, I'm spinning in circles, and could use some help. This seems like it should be easy. Thanks.

• Anthony Forloney: One of the PHP functions I was going to suggest was, array_walk_recursive which would not require you to do a loop. However, that function does not work if your key has an array value, as yours does. A loop maybe the only way. May I ask why without loops?
• Felix Kling: @Anthony Forloney: I am a bit confused. This function should do exactly what the OP wants. Can you explain better why it would not work? The only problem I see is that it will loop through all values even if a match was already found.
• dardub: Well when I'm checking if the value exists, it's already looping through all the values for the id (contained in an object) to match against. I'm just trying to cut down on the search time.
• Anthony Forloney: @Felix, I found this from the website: Any key that holds an array will not be passed to the function. Whereas the OP's array has keys that holds an array. Unless I am misinterpreting that quote, it seems that keys which has array values will not be passed into the function, which wouldn't be an answer to his question.
• Felix Kling: @Anthony Forloney: Yes, but that does not matter. It works recursively. The key, that holds the array will not be passed to the function, that is true. But the keys inside this (sub)array are passed. So it works exactly how you described it in the first place. Instead of e.g. operator, the elements in the subarray are passed (i.e. qty, id) and you can check against them. Have a look at the example in the docs... But as the OP only wants to search for id, array_walk is indeed easier.

Answer 1

array_walk() can be used to check whether a particular value is within the array; - it iterates through all the array elements which are passed to the function provided as second argument. For example, the function can be called as in the following code.

function checkValue($value, $key) {
 echo $value['id'];
}
$arr = array(
 'one' => array('id' => 1),
 'two' => array('id' => 2),
 'three' => array('id' => 3)
);
array_walk($arr, 'checkValue');

• Felix Kling: You should add a link to the documentation and also mention that you can pass a third parameter to array_walk which again will be passed to the callback function (i.e. this is the way to pass the id to search for).
• dardub: can I have the function return a bool? I'm having trouble getting that part to work?
• falomir: array_walk returns true or false but depending on whether the callback was successfully executed or not - you can use a a flag (a global variable) to indicate whether the value you are looking for was found or not.
• dardub: Thanks for the help falomir and Felix. I think I can get this working to suit my needs.

Answer 2

This function is useful in_array(211, $array['accessory']); It verifies the whole specified array to see if your value exists in there and returns true.

in_array

Answer 3

$map = array();
foreach ($arr as $v) {
 $map[$v['id']] = 1;
}
//then you can just do this as when needed
$exists = isset($map[211]);

Or if you need the data associated with it

$map = array();
foreach ($arr as $k => $v) {
 $map[$v['id']][$k] = $v;
}
print_r($map[211]);

Answer 4

<?php
//PHP 5.3 way to do it
function searchNestedArray(array $array, $search, $mode = 'value') {
 foreach (new RecursiveIteratorIterator(new RecursiveArrayIterator($array)) as $key => $value) {
 if ($search === ${${"mode"}})
 return true;
 }
 return false;
}
$data = array(
 array('abc', 'ddd'),
 'ccc',
 'bbb',
 array('aaa', array('yyy', 'mp' => 555))
);
var_dump(searchNestedArray($data, 555));

Answer 5

I used a static method because i needed it in a class, but if you want you can use it as a simple function.

/**
 * Given an array like this
 * array(
 * 'id' => "first",
 * 'title' => "First Toolbar",
 * 'class' => "col-md-12",
 * 'items' => array(
 * array(
 * 'tipo' => "clientLink",
 * 'id' => "clientLinkInsert"
 * )
 * )
 * )
 *
 * and array search like this
 * array("items", 0, "id")
 * 
 * Find the path described by the array search, in the original array
 *
 * @param array $array source array
 * @param array $search the path to the item es. ["items", 0, "tipo"]
 * @param null|mixed $defaultIfNotFound the default value if the value is not found
 *
 * @return mixed
 */
public static function getNestedKey($array, $search, $defaultIfNotFound = null)
{
 if( count($search) == 0 ) return $defaultIfNotFound;
 else{
 $firstElementSearch = self::array_kshift($search);
 if (array_key_exists($firstElementSearch, $array)) {
 if( count($search) == 0 )
 return $array[$firstElementSearch];
 else
 return self::getNestedKey($array[$firstElementSearch], $search, $defaultIfNotFound);
 }else{
 return $defaultIfNotFound;
 }
 }
}

Answer 6

You can use

Arr::getNestedElement($array, $keys, $default = null)

from this library to get value from multidimensional array using keys specified like 'key1.key2.key3' or ['key1', 'key2', 'key3'] and fallback to default value if no element was found. Using your example it will look like:

if (Arr::getNestedElement($array, 'accessory.id') == 211)

Answer 7

if there is a search based on a value in the array you can use the PHP array_filter which is intended for this purpose,

for retrieving sibling values like qty in your example

array_values(
 array_filter(
 $yourArray,
 fn ($inner)=> $inner['id'] == 211
 )
)[0]['qty'] ?? [];

or for retiring the inner array key like accessory209 in your example:

array_keys(
 array_filter(
 $yourArray,
 fn ($inner)=> $inner['id'] == 211
 )
)[0] ?? [];