Arrays and Iterators

JPHP has two useful classes for working with arrays and iterators. Our way is universal methods which can work with arrays and iterators.

• php\lib\Items - an util class with static methods
• php\util\Flow - flows are used for the lazy array/iterator operations to save the RAM memory.

Array Functions

The JPHP has own util class for working with iterators and arrays php\lib\Items, for example:

Why Items?

We cannot use Array because all methods work with not only arrays, List because it's a lexer keyword, Arr because it's an ugly reduction of the Array word, Collection - it's too long word.

use php\lib\Items;

$keys = Items::keys($array);

// instead of

$keys = array_keys($array);

• sizeof, count -> Items::count, supports iterators
• iterator_to_array, array_values -> Items::toArray
• ??? -> Items::toList, Items::toList([1, 2], 3, 4, [5]) -> [1, 2, 3, 4, 5]
• ??? -> Items::flatten
• usort, sort -> Items::sort
• ksort -> Items::sortByKeys
• array_push -> Items::push
• array_pop -> Items::pop
• array_shift -> Items::shift
• array_unshift -> Items::unshift

Flow class

Supports not only arrays, also iterators and traversable. Flow implements Iterator.

• array_map -> Flow::of($array)->map()
• array_filter -> Flow::of($array)->find(), Flow::of($array)->findOne()
• array_reduce -> Flow::of($array)->reduce()
• array_merge -> Flow::of($array1)->append($array2)->append(array3)->toArray()
• ???, foreach -> Flow::of(...)->each(), Flow::of(...)->eachSlice
• array_keys -> Flow::of(...)->keys()
• LimitIterator, array_filter -> Flow::of(...)->limit($n)
• ???, array_filter -> Flow::of(...)->skip($n)
• asort, usort -> Flow::of(...)->sort()
• ksort -> Flow::of(...)->sortByKeys()
• array_values -> Flow::of(...)->toArray()
• implode -> Flow::of(...)->toString()

Many methods of Flow return a new Flow instance, so you can use fluent interface to lazy manipulate arrays and iterators, for instance:

$someArray = [....];

$collection = Flow::of($someArray)
              ->filter(function($el) { return $el > 18; }) 
              ->map(function($el, $key) { return "[" . $el . "]"; });

foreach ($collection as $key => $value) {
   var_dump($value);
}

// You can use a flow instance only one time as a generator
// The next code will throw an exception
foreach ($collection ... ) { }