ListControl.js

Overview

Unlike some other programming languages (like PHP), JavaScript does not have an internal pointer for iterable objects. Though it is not a necessacity, it is a nice-to-have functionality is some situations.

ListControl.js aims to provide that functionality. It is extended from the native Array prototype, so you can use it like a normal Array with the internal pointer functionality attached.

Installation

npm install listcontrol

Usage

const ListControl = require('listcontrol');

const list = new ListControl('a', 'b', 'c');

OR with HTML:

<script src="path/to/listcontrol.min.js"></script>
<script>
const list = new ListControl('a', 'b', 'c');
</script>

Property

.index

The property is the main pointer. Though it is writable, you are highly discouraged from replacing the value of this property under most circumstances.

list.index
// -> 0

Methods

.current()

Returns the current item of the instance.

list.current()
// -> 'a'

.next()

Increments the pointer index by 1 if there is a next item in the instance. Returns the next item if there is a next item or undefined otherwise.

list.next()
// -> 'b'

list.index
// -> 1

list.next()
// -> 'c'

list.index
// -> 2

list.next()
// -> undefined

list.index
// -> 2

.previous

Increments the pointer index by 1 if there is a previous item in the instance. Returns the previous item if there is a previous item or undefined otherwise.

list.previous()
// -> 'b'

list.index
// -> 1

list.previous()
// -> 'a'

list.index
// -> 0

list.previous()
// -> undefined

list.index
// -> 0

.last()

Moves the pointer index to the last and returns the last item in the instance.

list.last()
// -> 'c'

list.index
// -> 2

.first()

Moves the pointer index to the start and returns the first item in the instance.

list.first()
// -> 'a'

list.index
// -> 0