PHP 8.1.0 RC 2 available for testing

Ds\Vector::reduce

(PECL ds >= 1.0.0)

Ds\Vector::reduceReduces the vector to a single value using a callback function

Description

public Ds\Vector::reduce(callable $callback, mixed $initial = ?): mixed

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

Liste de paramètres

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.

Valeurs de retour

The return value of the final callback.

Exemples

Exemple #1 Ds\Vector::reduce() with initial value example

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

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

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

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

Résultat de l'exemple ci-dessus est similaire à :

int(30)

Exemple #2 Ds\Vector::reduce() without an initial value example

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

var_dump($vector->reduce(function($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
?>

Résultat de l'exemple ci-dessus est similaire à :

int(21)
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