list_utilities #

A collection of basic extension methods for [Iterable]s, [List]s, and [Set]s.

See: num_utilities

Usage #

import 'package:list_utilities/list_utilities.dart';

Iterable Methods #

Methods extending [Iterable] are also be available on [List]s, [Set]s, or any other implementation of [Iterable].

random #

The [random] method returns a random value from the iterable.

final numbers = [0, 1, 2, 3, 4];
print(numbers.random()); // 3 (or any of the other numbers.)

matches #

The [matches] method returns true if the other iterable is the same length as the calling iterable and contains all of the same elements.

[matches] has an optional parameter, [ordered], which if true, requires the elements of each iterable to be in the same order to satisfy [matches].

final numbersA = {1, 2, 3, 4, 5};
final numbersB = {5, 4, 3, 2, 1};
print(numbersA.matches(numbersB)); // true
print(numbersA.matches(numbersB, ordered: true)); // false

List Methods #

removeRandom #

The [removeRandom] method removes and returns an element from the list at random.

final numbers = [0, 1, 2, 3, 4];
print(numbers.removeFirst()); // 3 (or any of the  other numbers.)
print(numbers); // [0, 1, 2, 4]

Note: [removeRandom] is included on [List]s and [Set]s, but not [Iterables] because [Iterable]s lack methods to remove elements without first converting it to a [List] or [Set].

removeNull #

The [removeNull] method removes all null values from the list.

final numbers = [0, 1, null, 3, null];
numbers.removeNull();
print(numbers); // [0, 1, 3]

removeFirst #

The [removeFirst] method removes the first item from the list.

final numbers = [0, 1, 2, 3, 4];
print(numbers.removeFirst()); // 0
print(numbers); // [1, 2, 3, 4]

removeFirstWhere #

The [removeFirstWhere] method iterates through the list and removes the first element that satisfies the test.

final numbers = [0, 1, 2, 3, 4];
numbers.removeFirstWhere((number) => number.isOdd);
print(numbers); // [0, 2, 3, 4]

removeLastWhere #

The [removeLastWhere] method iterates through the list in reverse and removes the first element that satisfies the test.

final numbers = [0, 1, 2, 3, 4];
numbers.removeLastWhere((number) => number.isOdd);
print(numbers); // [0, 1, 2, 4]

resizeAndFill #

The [resizeAndFill] method adds or removes elements from the list, setting any new values to the provided value.

final numbers = [0, 1, 2, 3, 4];
numbers.resizeAndFill(-2, 0);
print(numbers); // [0, 1, 2]
numbers.resizeAndFill(2, 0);
print(numbers); // [0, 1, 2, 0, 0]

resizeAndGenerate #

The [resizeAndGenerate] method adds or removes elements from the list, setting any new values with the provided generator.

final numbers = [0, 1, 2, 3, 4];
numbers.resizeAndGenerate(5, (index) => index);
print(numbers); // [0, 1, 2, 3, 4, 0, 1, 2, 3, 4]
numbers.resizeAndGenerate(-5, (index) => index);
print(numbers); // [0, 1, 2, 3, 4]

removeFrom #

The [removeFrom] method removes the specified number of elements, starting at the provided index.

final numbers = [0, 1, 2, 3, 4];
numbers.removeFrom(3, 2);
print(numbers); // [0, 1, 2]
numbers.removeFrom(0, 2);
print(numbers); // [2]

removeFromEnd #

The [removeFromEnd] method removes the specified number of elements from the end of the list.

final numbers = [0, 1, 2, 3, 4];
numbers.removeFromEnd(2);
print(numbers); // [0, 1, 2]

Set Methods #

removeRandom #

The [removeRandom] method removes and returns an element from the set at random.

final numbers = {0, 1, 2, 3, 4};
print(numbers.removeFirst()); // 3 (or any of the  other numbers.)
print(numbers); // [0, 1, 2, 4]

Note: [removeRandom] is included on [List]s and [Set]s, but not [Iterables] because [Iterable]s lack methods to remove elements without first converting it to a [List] or [Set].

+ operator #

The + operator returns a new [Set] by appending the second [Set]'s values to the end of the first [Set]s'.

final numbersA = {1, 2, 3};
final numbersB = {4, 5, 6};
print(numbersA + numbersB); // {1, 2, 3, 4, 5, 6}