Iterator Utility

Helpers for iterate and handle throught lists.

class Jar\Utilities\Utilities\IteratorUtility

---

Jar\Utilities\Utilities\IteratorUtility::sortArrayByColumn(&$arr, $col, $dir = SORT_ASC)

Sort array by column/key value.

Parameters:

• $arr (array) – Reference of array.
• $col (string) – The column/key name.
• $dir (int) – The direction SORT_ASC or SORT_DESC

Example:

$persons = [
   [
      'name' => 'peter',
      'age' => 34
   ],
   [
      'name' => 'klaus',
      'age' => 21
   ],
   [
      'name' => 'michael',
      'age' => 17
   ],
];

IteratorUtility::sortArrayByColumn($persons, 'age');

returns

[
   [
      'name' =>  'michael'
      'age' =>  17
   ],
   [
      'name' =>  'klaus'
      'age' =>  21
   ],
   [
      'name' =>  'peter'
      'age' =>  34
   ]
]

---

Jar\Utilities\Utilities\IteratorUtility::extractValuesViaGetMethod($listOfObjects, $methodName)

Extracts properties from objects via their get method.

Parameters:

• $listOfObjects (array) – List of objects.
• $methodName (string) – The name of the method, without the beginning ‘get’.

Returns:

Extracted values.

Example:

class Person
{
   private string $name;

   function __construct($name)
   {
      $this->name = $name;
   }

   public function getName(): string
   {
      return $this->name;
   }
};

/* ... */


$persons = [ new Person('klaus'), new Person('peter')];
$names = IteratorUtility::extractValuesViaGetMethod($persons, 'name');

var_dump($names);

returns

['klaus', 'peter']

---

Jar\Utilities\Utilities\IteratorUtility::extractValuesViaGetMethodFlattened($listOfObjects, $methodName, $keepKeys = false)

Extracts properties from objects via their get method and flattens the result.

Parameters:

• $listOfObjects (array) – List of objects.
• $methodName (string) – The name of the method, without the beginning ‘get’.
• $keepKeys (bool) – Keep keys in result. Will overwrite existing values for this key.

Returns:

Extracted flattened values.

Example:

class Element
{
   private array $items;

   function __construct($items)
   {
      $this->items = $items;
   }

   public function getItems(): array
   {
      return $this->items;
   }
};

/* ... */


$elements = [
   new Element(
      [
         'a' => 1,
         'b' => 2,
         'c' => 3,
         'd' => 4
      ]
   ),
   new Element([
      'e' => 5,
      'f' => 6,
      'g' => 7,
      'a' => 8
   ])
];

// without "keepKeys"

$allItems = IteratorUtility::extractValuesViaGetMethodFlattened($elements, 'items');
var_dump($allItems);
/*
   Result:
      0 =>  1
      1 =>  2
      2 =>  3
      3 =>  4
      4 =>  5
      5 =>  6
      6 =>  7
      7 =>  8
*/

// with "keepKeys"

$allItems = IteratorUtility::extractValuesViaGetMethodFlattened($elements, 'items', true);
var_dump($allItems);
/*
   Result:
      'a' =>  8
      'b' =>  2
      'c' =>  3
      'd' =>  4
      'e' =>  5
      'f' =>  6
      'g' =>  7
*/

---

Jar\Utilities\Utilities\IteratorUtility::callMethod($listOfObjects, $method)

Calls a method in each object and returns the results.

Parameters:

• $listOfObjects (array) – List of objects.
• $method (string) – name of the method.

Returns:

List of method results.

Example:

class Element
{
   private int $number;

   function __construct($number)
   {
      $this->number = $number;
   }

   public function add(): int
   {
      return $this->number + 1;
   }
};

/* ... */

$numbers = [ new Element(5), new Element(2) ];

$addedNumbers = IteratorUtility::callMethod($numbers, 'add');

var_dump($addedNumbers);

returns

[6, 3]

---

Jar\Utilities\Utilities\IteratorUtility::compact($arr)

Returns a copy of the list with all falsy values (null, 0, ‘’) removed.

Parameters:

• $arr (array) – List with values.

Returns:

List without falsy values

Example:

IteratorUtility::compact(['hello', null, '', 0, 'world'])

returns

['hello', 'world']

---

Jar\Utilities\Utilities\IteratorUtility::flatten($arr)

Flattens a nested array.

Parameters:

• $arr (array) – The nested array.

Returns:

The flat array.

Example:

IteratorUtility::flatten([
   [1, 2, 3],
   [4, 5],
   [6]
]);

returns

[1, 2, 3, 4, 5, 6]

---

Jar\Utilities\Utilities\IteratorUtility::filter($arr, $func)

Filters a list with a closure condition

Parameters:

• $arr (array) – The array.
• $func (callable) – The filter closure.

Returns:

The filtered result.

Example:

IteratorUtility::filter(
   [1, 2, 3, 4, 5, 6],
   function($value) {
      return (bool) ($value % 2);
   }
);

returns

[1, 3, 5]

---

Jar\Utilities\Utilities\IteratorUtility::map($arr, $func)

Iterates each item and maps the new value throught a function.

Parameters:

• $arr (array) – The array.
• $func The transformation function (receives three parametes (callable) –
  1. value, 2. key, 3. current transformated list).

Returns:

The mapped array.

Example:

IteratorUtility::map(
   [1, 2, 3, 4, 5, 6],
   function($value) {
      return $value * 2;
   }
);

returns

[2, 4, 6, 8, 10, 12]

---

Jar\Utilities\Utilities\IteratorUtility::first($arr)

Returns the first element from a list.

Parameters:

• $arr (array) – The array.

Returns:

First element.

Example:

IteratorUtility::first(['hello', 'world'])

returns

'hello'

---

Jar\Utilities\Utilities\IteratorUtility::pluck($arr, $key)

Extracts a the value of a certain key.

Parameters:

• $arr (array) – The array.
• $key (string) – The key.

Returns:

The extracted values.

Example:

$persons = [
   [
      'name' => 'peter',
      'age' => 34
   ],
   [
      'name' => 'klaus',
      'age' => 21
   ],
   [
      'name' => 'michael',
      'age' => 17
   ],
];

IteratorUtility::pluck($persons, 'name');

returns

['peter' , 'klaus' , 'michael']

---

Jar\Utilities\Utilities\IteratorUtility::contains($arr, $needle)

Checks if a value exist in an array.

Parameters:

• $arr (array) – The array.
• $needle (string) – The value to check.

Returns:

Check result.

Example:

// true
IteratorUtility::contains([1, 2, 3, 4, 5, 6], 2);

// false
IteratorUtility::contains([1, 2, 3, 4, 5, 6], 7);

---

Jar\Utilities\Utilities\IteratorUtility::whitelist($array, $whitelist)

Returns only array entries listed in a whitelist.

Parameters:

• $array (array) – Original array to operate on.
• $whitelist (array) – Keys you want to keep.

Returns:

The whitelisted entries.

Example:

IteratorUtility::whitelist([
   'a' => 1,
   'b' => 2,
   'c' => 3,
   'd' => 4
], ['a', 'c']);

returns

[
   'a' =>  1,
   'c' =>  3
]

---

Jar\Utilities\Utilities\IteratorUtility::whitelistList($array, $whitelist)

Returns only nested array entries listed in a whitelist.

Parameters:

• $array (array) – List of nested array items
• $whitelist (array) – Keys you want to keep.

Returns:

The whitelisted entries.

Example:

IteratorUtility::whitelistList([
   [
      'a' => 1,
      'b' => 2,
      'c' => 3,
      'd' => 4
   ],
   [
      'a' => 5,
      'b' => 6,
      'c' => 7,
      'd' => 8
   ]
], ['a', 'c'])

returns

[
   [
      'a' =>  1,
      'c' =>  3
   ],
   [
      'a' =>  5,
      'c' =>  7
   ]
]

---

Jar\Utilities\Utilities\IteratorUtility::indexBy($arr, $key)

Create a indexed list based on key values.

Parameters:

• $array (array) – The array.
• $key (string) – The index key name.

Returns:

The indexed List.

Example:

$persons = [
   [
      'id' => 5,
      'name' => 'peter',
   ],
   [
      'id' => 2,
      'name' => 'klaus',
   ],
   [
      'id' => 3,
      'name' => 'michael',
   ],
];

var_dump($persons);
/*
   Result:
   [
      0 => [
         'id' =>  5
         'name' =>  'peter'
      ],
      1 => [
         'id' =>  2
         'name' =>  'klaus'
      ],
      2 => [
         'id' =>  3
         'name' =>  'michael'
      ]
   ]
*/

$indexedPersons = IteratorUtility::indexBy($persons, 'id');

var_dump($indexedPersons);
/*
   Result:
   [
      5 => [
         'id' =>  5
         'name' =>  'peter'
      ],
      2 => [
         'id' =>  2
         'name' =>  'klaus'
      ],
      3 => [
         'id' =>  3
         'name' =>  'michael'
      ]
   ]
*/