lists.md

Lists

A list is a data type which can contain a sequence of values.

Lists can be created in Voxel using the following syntax:

var item = "banana";

var list = [123, true, null, "hello", item, [3, 2, 1], {object: true}];

List items are enclosed in square brackets ([ and ]), and are delimeted by commas (,). Items can be of any type.

Reference

List

The list data type.

length: Number

The number of items in the list.

push(value: *): Number

Push an item (value) onto the end of the list and return the new list length.

pop(): *

Pop the last item from the list (which removes it) and return that item.

unshift(value: *): Number

Insert an item (value) at the start of the list and return the new list length.

shift(): *

Remove the first item from the list and return that item.

insert(index: Number, value: *): *

Insert an item (value) onto the list at a specified index (index) and return that item.

removeAt(index: Number): *

Remove an item from the list at a specified index (index) and return that item.

indexOf(value: *): Number

Find the index of the first occurrence of a value (value) in the list and return it. If equality is true, then perform equality checking; otherwise, perform identity checking.

If the item cannot be found, -1 will be returned instead.

contains(value: *, equality: Boolean): Boolean

Return true if a value (value) is in the list; otherwise, return false. If equality is true, then perform equality checking; otherwise, perform identity checking.

remove(value: *): Boolean

Remove the first occurrence of a value (value) in the list. Return true if it was found and removed; otherwise, return false. If equality is true, then perform equality checking; otherwise, perform identity checking.

clear()

Remove all values in the list.

join(delimeter: String = ","): String

Join all list values into a string by using the delimeter (delimeter) to separate each item, and return it.

concat(source: List<*>): List<*>

Concatenate the list with items from the source list (source), mutating the original list. The concatenated list will be returned.

forEach(callback: function(item: *, index: Number))

Iterate through the list and call a callback function (callback) for every item with arguments that reference the item (item) and the item's index (index).

map(callback: function(item: *, index: Number): *): List<*>

Iterate through the list and call a callback function (callback) for every item with arguments that reference the item (item) and the item's index (index).

The callback function must return a new value. A new list will be returned when calling map containing all values returned from calling the callback function for every item.

filter(callback: function(item: *, index: Number): Boolean): List<*>

Iterate through the list and call a callback function (callback) for every item with arguments that reference the item (item) and the item's index (index).

The callback function must return a boolean value. A new list will be returned when calling filter containing all values from the original list where the callback function returned true.

find(callback: function(item: *, index: Number): Boolean): *

Iterate through the list until the callback function (callback) called for every item returns true. Return the list item that caused the callback function to return true. The callback function is called with arguments that reference the item (item) and the item's index (index).

If the callback function never returns true, then null will be returned instead.

findIndex(callback: function(item: *, index: Number): Boolean): Number

Iterate through the list until the callback function (callback) called for every item returns true. Return the index of the list item that caused the callback function to return true. The callback function is called with arguments that reference the item (item) and the item's index (index).

If the callback function never returns true, then -1 will be returned instead.

reduce(callback: function(accumulator: *, item: *, index: Number): *, initialValue: *): *

Iterate through the list and call a callback function (callback) for every item. The callback will be called with arguments for the previous call's return value or the initial provided value (initialValue) if it is the first call (accumulator), the current list item (item) and the item's index (index). The last call's return value will be used as the return value of reduce.