list_utilities 1.0.0 list_utilities: ^1.0.0 copied to clipboard
A collection of basic extension methods for Iterables, Lists, and Sets.
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 #
getRandom #
The [getRandom] method returns a new set containing random elements from the set.
final numbers = [0, 1, 2, 3, 4];
print(numbers.getRandom(3)); // [3, 1, 4] (or any other combination of numbers.)
removeRandom #
The [removeRandom] method removes and returns an element from the list at random.
final numbers = [0, 1, 2, 3, 4];
print(numbers.removeRandom()); // 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]
transform #
The [transform] method updates the element at the provided index to the value returned by the provided transformer.
final numbers = [0, 1, 2, 3, 4];
numbers.transform(2, (number) => number * 2);
print(numbers); // [0, 1, 4, 3, 4]
transformAll #
The [transformAll] method updates every element in a list to the value returned by the provided transformer.
final numbers = [0, 1, 2, 3, 4];
numbers.transformAll((number) => number * 2);
print(numbers); // [0, 2, 4, 6, 8]
count #
The [count] method returns the number of instances there are of the provided object in a list.
final numbers = [0, 0, 1, 2, 1, 0, 0];
print(numbers.count(0)); // 4
print(numbers.count(1)); // 2
print(numbers.count(2)); // 1
Set Methods #
getRandom #
The [getRandom] method returns a new set containing random elements from the set.
final numbers = {0, 1, 2, 3, 4};
print(numbers.getRandom(3)); // {3, 1, 4} (or any other combination of numbers.)
removeRandom #
The [removeRandom] method removes and returns an element from the set at random.
final numbers = {0, 1, 2, 3, 4};
print(numbers.removeRandom()); // 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].
removeFirst #
TODO:
removeLast #
TODO:
+ 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}