Ds\Sequence::reduce

(PECL ds >= 1.0.0)

Ds\Sequence::reduceReduces the sequence to a single value using a callback function

Açıklama

abstract public Ds\Sequence::reduce ( callable $callback [, mixed $initial ] ) : mixed

Reduces the sequence to a single value using a callback function.

Değiştirgeler

callback
callback ( mixed $carry , mixed $value ) : mixed
carry

The return value of the previous callback, or initial if it's the first iteration.

value

The value of the current iteration.

initial

The initial value of the carry value. Can be NULL.

Dönen Değerler

The return value of the final callback.

Örnekler

Örnek 1 Ds\Sequence::reduce() with initial value example

<?php
$sequence 
= new \Ds\Vector([123]);

$callback = function($carry$value) {
    return 
$carry $value;
};

var_dump($sequence->reduce($callback5));

// Iterations:
//
// $carry = $initial = 5
//
// $carry = $carry * 1 =  5
// $carry = $carry * 2 = 10
// $carry = $carry * 3 = 30
?>

Yukarıdaki örnek şuna benzer bir çıktı üretir:

int(30)

Örnek 2 Ds\Sequence::reduce() without an initial value example

<?php
$sequence 
= new \Ds\Vector([123]);

var_dump($sequence->reduce(function($carry$value) {
    return 
$carry $value 5;
}));

// Iterations:
//
// $carry = $initial = null
//
// $carry = $carry + 1 + 5 =  6
// $carry = $carry + 2 + 5 = 13
// $carry = $carry + 3 + 5 = 21
?>

Yukarıdaki örnek şuna benzer bir çıktı üretir:

int(21)