org.apache.commons.collections4.bag

## Class HashBag<E>

- java.lang.Object
- - org.apache.commons.collections4.bag.AbstractMapBag<E>
  - - org.apache.commons.collections4.bag.HashBag<E>

- All Implemented Interfaces:
    Serializable, Iterable<E>, Collection<E>, Bag<E>

      public class HashBag<E>
      extends AbstractMapBag<E>
      implements Serializable

  Implements `Bag`, using a `HashMap` to provide the data storage. This is the standard implementation of a bag.

  A `Bag` stores each object in the collection together with a count of occurrences. Extra methods on the interface allow multiple copies of an object to be added or removed at once. It is important to read the interface javadoc carefully as several methods violate the `Collection` interface specification.

  Since:
    3.0 (previously in main package v2.0)
  Version:
    $Id: HashBag.java 1685902 2015-06-16 20:13:13Z tn $
  See Also:
    Serialized Form

- - ### Nested Class Summary

    - ### Nested classes/interfaces inherited from class org.apache.commons.collections4.bag.AbstractMapBag

      `AbstractMapBag.MutableInteger`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `HashBag()` Constructs an empty `HashBag`.
    `HashBag(Collection<? extends E> coll)` Constructs a bag containing all the members of the given collection.

  - ### Method Summary

    - ### Methods inherited from class org.apache.commons.collections4.bag.AbstractMapBag

      `add, add, addAll, clear, contains, containsAll, doReadObject, doWriteObject, equals, getCount, getMap, hashCode, isEmpty, iterator, remove, remove, removeAll, retainAll, size, toArray, toArray, toString, uniqueSet`

    - ### Methods inherited from class java.lang.Object

      `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### HashBag

          public HashBag()

      Constructs an empty `HashBag`.

    - #### HashBag

          public HashBag(Collection<? extends E> coll)

      Constructs a bag containing all the members of the given collection.
      Parameters:
        `coll` - a collection to copy into this bag

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