Get all values from multidimensional array - php

Question

Let's say, I have an array like this:
$array = [
'car' => [
'BMW' => 'blue',
'toyota' => 'gray'
],
'animal' => [
'cat' => 'orange',
'horse' => 'white'
]
];
Then, I want to get all the values (the colour, 'blue', 'gray', 'orange', 'white') and join them into a single array. How do I do that without using foreach twice?
Thanks in advance.

Answer 1

TL;DR
$result = call_user_func_array('array_merge', $array);
Credit: How to "flatten" a multi-dimensional array to simple one in PHP?
In your use case, you should use it like this:
<?php
$array = [
'car' => [
'BMW' => 'blue',
'toyota' => 'gray'
],
'animal' => [
'cat' => 'orange',
'horse' => 'white'
]
];
$result = call_user_func_array('array_merge', $array);
$result = array_values($result);
//$result = ['blue', 'gray', 'orange', 'white']

Answer 2

Old but as far i see not really a "working on all cases" function posted.
So here is the common classic recursively function:
function getArrayValuesRecursively(array $array)
{
$values = [];
foreach ($array as $value) {
if (is_array($value)) {
$values = array_merge($values,
getArrayValuesRecursively($value));
} else {
$values[] = $value;
}
}
return $values;
}
Example array:
$array = [
'car' => [
'BMW' => 'blue',
'toyota' => 'gray'
],
'animal' => [
'cat' => 'orange',
'horse' => 'white'
],
'foo' => [
'bar',
'baz' => [
1,
2 => [
2.1,
'deep' => [
'red'
],
2.2,
],
3,
]
],
];
Call:
echo var_export(getArrayValuesRecursively($array), true) . PHP_EOL;
Result:
// array(
// 0 => 'blue',
// 1 => 'gray',
// 2 => 'orange',
// 3 => 'white',
// 4 => 'bar',
// 5 => 1,
// 6 => 2.1,
// 7 => 'red',
// 8 => 2.2,
// 9 => 3,
// )

Answer 3

Try this:
function get_values($array){
foreach($array as $key => $value){
if(is_array($array[$key])){
print_r (array_values($array[$key]));
}
}
}
get_values($array);

Answer 4

How do I do that without using foreach twice?
First use RecursiveIteratorIterator class to flatten the multidimensional array, and then apply array_values() function to get the desired color values in a single array.
Here are the references:
RecursiveIteratorIterator class
array_values()
So your code should be like this:
$iterator = new RecursiveIteratorIterator(new RecursiveArrayIterator($array));
$flatten_array = array_values(iterator_to_array($iterator,true));
// display $flatten_array
echo "<pre>"; print_r($flatten_array);
Here's the live demo

Answer 5

Here's a recursive function that gives you both the ability to get an array of those endpoint values, or to get an array with all keys intact, but just flattened.
Code:
<?php
$array = [
'car' => [
'BMW' => 'blue',
'toyota' => 'gray'
],
'animal' => [
'cat' => 'orange',
'horse' => 'white'
]
];
//
print "\n<br> Array (Original): ".print_r($array,true);
print "\n<br> Array (Flattened, With Keys): ".print_r(FlattenMultiArray($array,true),true);
print "\n<br> Array (Flattened, No Keys): ".print_r(FlattenMultiArray($array,false),true);
//
function FlattenMultiArray($array,$bKeepKeys=true,$key_prefix='')
{
//
$array_flattened=Array();
//
foreach($array as $key=>$value){
//
if(Is_Array($value)){
$array_flattened=Array_Merge(
$array_flattened,
FlattenMultiArray($value,$bKeepKeys,$key)
);
}
else{
if($bKeepKeys){
$array_flattened["{$key_prefix}_{$key}"]=$value;
}
else{
$array_flattened[]=$value;
}
}
}
return $array_flattened;
}
?>
Outputs:
<br> Array (Original): Array
(
[car] => Array
(
[BMW] => blue
[toyota] => gray
)
[animal] => Array
(
[cat] => orange
[horse] => white
)
)
<br> Array (Flattened, With Keys): Array
(
[car_BMW] => blue
[car_toyota] => gray
[animal_cat] => orange
[animal_horse] => white
)
<br> Array (Flattened, No Keys): Array
(
[0] => blue
[1] => gray
[2] => orange
[3] => white
)

Answer 6

If you don't care about the indexes, then this should do it:
$colors = array();
foreach ($array as $item) {
$colors = array_merge($colors, array_values($item));
}
If you want to keep the indexes you could use:
$colors = array();
foreach ($array as $item) {
// this leaves you open to elements overwriting each other depending on their keys
$colors = array_merge($colors, $item);
}
I hope this helps.

Answer 7

what about this one?It works with ANY array depth.
private function flattenMultiArray($array)
{
$result = [];
self::flattenKeyRecursively($array, $result, '');
return $result;
}
private static function flattenKeyRecursively($array, &$result, $parentKey)
{
foreach ($array as $key => $value) {
$itemKey = ($parentKey ? $parentKey . '.' : '') . $key;
if (is_array($value)) {
self::flattenKeyRecursively($value, $result, $itemKey);
} else {
$result[$itemKey] = $value;
}
}
}
P.S. solution is not mine, but works perfectly, and I hope it will help someone.
Original source:
https://github.com/letsdrink/ouzo/blob/master/src/Ouzo/Goodies/Utilities/Arrays.php