Merge pull request #5 from sebastiandedeyne/master

Added array_flatten

Author: freekmurze

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 All Notable changes to `array-functions` will be documented in this file
 
+## 1.8.0 - 2016-03-08
+
+### Added
+- array_flatten function
+
 ## 1.7.0 - 2015-11-18
 
 ### Added

README.md

@@ -119,6 +119,20 @@ function array_split(array $array, $numberOfPieces = 2, $preserveKeys = false)
 function array_merge_values(array ... $arrays)
 ```
 
+### array_flatten
+```php
+/**
+ * Flatten an array of arrays. The `$levels` parameter specifies how deep you want to
+ * recurse in the array. If `$levels` is -1, the function will recurse infinitely.
+ *
+ * @param array $array
+ * @param int $levels
+ *
+ * @return array
+ */
+function array_flatten(array $array, $levels = -1)
+```
+
 ## Change log
 
 Please see [CHANGELOG](CHANGELOG.md) for more information what has changed recently.

src/array_functions.php

@@ -140,3 +140,34 @@ function array_merge_values(array ...$arrays)
 
     return array_values(array_unique($allValues));
 }
+
+/**
+ * Flatten an array of arrays. The `$levels` parameter specifies how deep you want to
+ * recurse in the array. If `$levels` is -1, the function will recurse infinitely.
+ *
+ * @param array $array
+ * @param int   $levels
+ *
+ * @return array
+ */
+function array_flatten(array $array, $levels = -1)
+{
+    if ($levels === 0) {
+        return $array;
+    }
+
+    $flattened = [];
+
+    if ($levels !== -1) {
+        --$levels;
+    }
+
+    foreach ($array as $element) {
+        $flattened = array_merge(
+            $flattened,
+            is_array($element) ? array_flatten($element, $levels) : [$element]
+        );
+    }
+
+    return $flattened;
+}

tests/ArrayFlattenTest.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace Spatie\Test;
+
+use function spatie\array_flatten;
+
+class ArrayFlattenTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @test
+     */
+    public function it_flattens_an_array()
+    {
+        $this->assertEquals(
+            ['a', 'b'],
+            array_flatten(['a', ['b']])
+        );
+    }
+
+    /**
+     * @test
+     */
+    public function it_recursively_flattens_an_array()
+    {
+        $this->assertEquals(
+            ['a', 'b', 'c', 'd', 'e'],
+            array_flatten(['a', ['b', ['c'], 'd'], 'e'])
+        );
+    }
+
+    /**
+     * @test
+     */
+    public function it_recursively_flattens_an_array_to_a_certain_level()
+    {
+        $this->assertEquals(
+            ['a', 'b', ['c'], 'd', 'e'],
+            array_flatten(['a', ['b', ['c'], 'd'], 'e'], 1)
+        );
+    }
+
+    /**
+     * @test
+     */
+    public function it_doesnt_flatten_if_the_amount_of_levels_is_0()
+    {
+        $this->assertEquals(
+            ['a', ['b', ['c'], 'd'], 'e'],
+            array_flatten(['a', ['b', ['c'], 'd'], 'e'], 0)
+        );
+    }
+}