# Ds\Vector::reduce

(PECL ds >= 1.0.0)

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

### Descripción

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

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

### Parámetros

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.

### Valores devueltos

The return value of the final callback.

### Ejemplos

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

<?php
\$vector
= new \Ds\Vector([1, 2, 3]);

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

var_dump(\$vector->reduce(\$callback, 5));

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

El resultado del ejemplo sería algo similar a:

int(30)

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

<?php
\$vector
= new \Ds\Vector([1, 2, 3]);

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
?>

El resultado del ejemplo sería algo similar a:

int(21)