reduce.md

reduce

Description

Returns the accumulated value of iteratively reduce the collection using a function that receives the accumulated value and returns a new one in each iteration

Parameters

fn

Function which reduce the collection calculating the accumulated value.

coll

Collection of values to be reduced by the function.

initial

initial value that will be used as accumulated value for with the first item in the collection.

Examples

A total amount calculator of a shopping cart:

<?php

use function Lambdish\Phunctional\reduce;

return reduce(
    function ($acc, array $item) {
        return $acc + ($item['quantity'] * $item['price']);
    }, 
    [
        'apple'     => ['quantity' => 2, 'price' => 1.2],
        'orange'    => ['quantity' => 1, 'price' => 3],
        'pineapple' => ['quantity' => 5, 'price' => 1],
    ]
);
            
// => 10.4