add array_split

Author: freekmurze

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 All Notable changes to `array-functions` will be documented in this file
 
+## 1.6.0 - 2015-10-28
+
+### Added
+- array_split function
+
 ## 1.5.0 - 2015-06-29
 
 ### Added

README.md

@@ -95,6 +95,19 @@ function array_keys_exist($needles, array $haystack)
 function array_split_filter(array $array, callable $callback)
 ```
 
+### array_split
+```php
+/**
+ * Split an array in the given amount of pieces.
+ *
+ * @param array $array
+ * @param int $numberOfPieces
+ * @param bool $preserveKeys
+ * @return array
+ */
+function array_split(array $array, $numberOfPieces = 2, $preserveKeys = false)
+```
+
 ## Change log
 
 Please see [CHANGELOG](CHANGELOG.md) for more information what has changed recently.

src/array_functions.php

@@ -6,7 +6,7 @@
  * Get a random value from an array.
  *
  * @param array $array
- * @param int $numReq  The amount of values to return
+ * @param int   $numReq The amount of values to return
  *
  * @return mixed
  */
@@ -50,7 +50,7 @@ function array_rand_weighted(array $array)
  * Determine if all given needles are present in the haystack.
  *
  * @param array|string $needles
- * @param array $haystack
+ * @param array        $haystack
  *
  * @return bool
  */
@@ -67,7 +67,7 @@ function values_in_array($needles, array $haystack)
  * Determine if all given needles are present in the haystack as array keys.
  *
  * @param array|string $needles
- * @param array $haystack
+ * @param array        $haystack
  *
  * @return bool
  */
@@ -89,7 +89,7 @@ function array_keys_exist($needles, array $haystack)
  *
  * Array keys are preserved.
  *
- * @param array $array
+ * @param array    $array
  * @param callable $callback
  *
  * @return array
@@ -98,9 +98,29 @@ function array_split_filter(array $array, callable $callback)
 {
     $passesFilter = array_filter($array, $callback);
 
-    $negatedCallback = function ($item) use ($callback) { return ! $callback($item); };
+    $negatedCallback = function ($item) use ($callback) { return !$callback($item); };
 
     $doesNotPassFilter = array_filter($array, $negatedCallback);
 
     return [$passesFilter, $doesNotPassFilter];
 }
+
+/**
+ * Split an array in the given amount of pieces.
+ *
+ * @param array $array
+ * @param int   $numberOfPieces
+ * @param bool  $preserveKeys
+ *
+ * @return array
+ */
+function array_split(array $array, $numberOfPieces = 2, $preserveKeys = false)
+{
+    if (count($array) === 0) {
+        return [];
+    }
+
+    $splitSize = ceil(count($array) / $numberOfPieces);
+
+    return array_chunk($array, $splitSize, $preserveKeys);
+}

tests/ArraySplitTest.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace Spatie\Test;
+
+use function spatie\array_split;
+
+class ArraySplitTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @test
+     */
+    public function it_can_handle_an_empty_array()
+    {
+        $this->assertSame(array_split([]), []);
+    }
+
+    /**
+     * @test
+     */
+    public function it_splits_an_array_in_two_by_default()
+    {
+        $this->assertSame(array_split(['a', 'b']), [['a'], ['b']]);
+    }
+
+    /**
+     * @test
+     */
+    public function it_splits_an_array_in_two_by_default_while_preserving_keys()
+    {
+        $this->assertSame(array_split(['a' => 1, 'b' => 2], 2, true), [['a' => 1], ['b' => 2]]);
+    }
+
+    /**
+     * @dataProvider arrayProvider
+     *
+     * @test
+     *
+     * @param $array
+     * @param $splitIntoNumber
+     * @param $expectedArray
+     */
+    public function it_can_split_an_array_in_equal_pieces($array, $splitIntoNumber, $expectedArray)
+    {
+        $this->assertSame($expectedArray, array_split($array, $splitIntoNumber));
+    }
+
+    public function arrayProvider()
+    {
+        return [
+            [
+                ['a', 'b', 'c', 'd'], 2, [['a', 'b'], ['c', 'd']],
+            ],
+            [
+                ['a', 'b', 'c', 'd', 'e'], 2, [['a', 'b', 'c'], ['d', 'e']],
+            ],
+            [
+                ['a', 'b', 'c', 'd', 'e'], 3, [['a', 'b'], ['c', 'd'], ['e']],
+            ],
+        ];
+    }
+}