mapKey()

The mapKey() method all similar to map(), but this applies to keys

Example.php

<?php use kim\present\utils\arrays\ArrayUtils;

$arrayUtils = ArrayUtils::from(range(1,5));

//Squared all elements
$arrayUtils->mapKey(function($num){ return "$num * $num"; });
// expected output: [
//  "1 * 1"   => 1,
//  "2 * 2"   => 2,
//  "3 * 3"   => 3,
//  "4 * 4"   => 4,
//  "5 * 5"   => 5
//]

Syntax

$arrayUtils->mapKey(callable $callback) : ArrayUtils;

Parameter

• $callback

  A function that produces an element of the new Array, taking three arguments:

  • $value The current element being processed in the array.

  • $key The index of the current element being processed in the array.

  • $array The array every was called upon.

Return value

• A new array with each element being the result of the callback function.

Prefixing

$arrayUtils->mapKeyAs(callable $callback) : array;

ArrayUtils::mapKeyFrom(iterable $from, callable $callback) : ArrayUtils;

ArrayUtils::mapKeyFromAs(iterable $from, callable $callback) : array;

References

map()