Package net.paulem.arcana.utils

Class ArraysUtils

java.lang.Object
net.paulem.arcana.utils.ArraysUtils
public class ArraysUtils extends Object
Utility methods for working with arrays and collections, such as picking random elements, computing differences, excluding elements, and reversing arrays.

  • Constructor Summary

    Constructors
    Constructor
    Description
    ArraysUtils()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static <T> List<T>
    difference(List<T> a, List<T> b)
    Computes the set difference between two lists, i.e. the elements of a that are not present in b.
    static <T> T[]
    excludeElements(T[] array, Collection<T> toExclude)
    Creates a copy of the given array with all elements contained in toExclude removed.
    static <T> T
    getRandom(Collection<T> collection)
    Picks a random element from the given collection.
    static <T> T
    getRandom(List<T> list)
    Picks a random element from the given list.
    static <T> T
    getRandom(T[] array)
    Picks a random element from the given array.
    static <T> T[]
    invertArray(T[] array)
    Reverses the given array in place.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • ArraysUtils

      public ArraysUtils()

  • Method Details

    • getRandom

      public static <T> T getRandom(T[] array)
      Picks a random element from the given array.
      Type Parameters:
      T - the type of the elements
      Parameters:
      array - the array to pick from
      Returns:
      a randomly chosen element of the array

    • getRandom

      public static <T> T getRandom(List<T> list)
      Picks a random element from the given list.
      Type Parameters:
      T - the type of the elements
      Parameters:
      list - the list to pick from
      Returns:
      a randomly chosen element of the list

    • getRandom

      public static <T> T getRandom(Collection<T> collection)
      Picks a random element from the given collection. The collection is copied into a list before an element is chosen.
      Type Parameters:
      T - the type of the elements
      Parameters:
      collection - the collection to pick from
      Returns:
      a randomly chosen element of the collection

    • difference

      public static <T> List<T> difference(List<T> a, List<T> b)
      Computes the set difference between two lists, i.e. the elements of a that are not present in b.
      Type Parameters:
      T - the type of the elements
      Parameters:
      a - the list to filter
      b - the list of elements to exclude
      Returns:
      a new list containing the elements of a that are not in b

    • excludeElements

      public static <T> T[] excludeElements(T[] array, Collection<T> toExclude)
      Creates a copy of the given array with all elements contained in toExclude removed.
      Type Parameters:
      T - the type of the elements
      Parameters:
      array - the array to filter
      toExclude - the elements to exclude from the result
      Returns:
      a new array containing only the elements of array that are not in toExclude

    • invertArray

      public static <T> T[] invertArray(T[] array)
      Reverses the given array in place.
      Type Parameters:
      T - the type of the elements
      Parameters:
      array - the array to reverse
      Returns:
      the same array instance, with its elements in reversed order