Class ArrayUtils


  • class ArrayUtils
    extends java.lang.Object

    Operations on arrays, primitive arrays (like int[]) and primitive wrapper arrays (like Integer[]).

    This class tries to handle null input gracefully. An exception will not be thrown for a null array input. However, an Object array that contains a null element may throw an exception. Each method documents its behaviour.

    Package private, might move to an internal package if this needs to be public.

    #ThreadSafe#

    Since:
    4.2 (Copied from Apache Commons Lang.)
    • Field Summary

      Fields 
      Modifier and Type Field Description
      (package private) static int INDEX_NOT_FOUND
      The index value when an element is not found in a list or array: -1.
    • Constructor Summary

      Constructors 
      Constructor Description
      ArrayUtils()  
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      (package private) static boolean contains​(java.lang.Object[] array, java.lang.Object objectToFind)
      Checks if the object is in the given array.
      (package private) static int indexOf​(java.lang.Object[] array, java.lang.Object objectToFind, int startIndex)
      Finds the index of the given object in the array starting at the given index.
      (package private) static <T> int indexOf​(T[] array, java.lang.Object objectToFind)
      Finds the index of the given object in the array.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • INDEX_NOT_FOUND

        static final int INDEX_NOT_FOUND
        The index value when an element is not found in a list or array: -1. This value is returned by methods in this class and can also be used in comparisons with values returned by various method from List.
        See Also:
        Constant Field Values
    • Constructor Detail

      • ArrayUtils

        ArrayUtils()
    • Method Detail

      • contains

        static boolean contains​(java.lang.Object[] array,
                                java.lang.Object objectToFind)

        Checks if the object is in the given array.

        The method returns false if a null array is passed in.

        Parameters:
        array - the array to search through
        objectToFind - the object to find
        Returns:
        true if the array contains the object
      • indexOf

        static <T> int indexOf​(T[] array,
                               java.lang.Object objectToFind)

        Finds the index of the given object in the array.

        This method returns INDEX_NOT_FOUND (-1) for a null input array.

        Parameters:
        array - the array to search through for the object, may be null
        objectToFind - the object to find, may be null
        Returns:
        the index of the object within the array, INDEX_NOT_FOUND (-1) if not found or null array input
      • indexOf

        static int indexOf​(java.lang.Object[] array,
                           java.lang.Object objectToFind,
                           int startIndex)

        Finds the index of the given object in the array starting at the given index.

        This method returns INDEX_NOT_FOUND (-1) for a null input array.

        A negative startIndex is treated as zero. A startIndex larger than the array length will return INDEX_NOT_FOUND (-1).

        Parameters:
        array - the array to search through for the object, may be null
        objectToFind - the object to find, may be null
        startIndex - the index to start searching at
        Returns:
        the index of the object within the array starting at the index, INDEX_NOT_FOUND (-1) if not found or null array input