LongSet

All Superinterfaces:

LongCollection, LongIterable

All Known Implementing Classes:

AbstractLongSet, LongHashSet
```
public interface LongSet
extends LongCollection
```
A collection that contains no duplicates. In other words, for two set elements e1 and e2, e1.equals(e2) returns false. There are additional stipulations on add, equals and hashCode, as well as the requirements that constructors do not permit duplicate elements. The Set interface is incompatible with List; you cannot implement both simultaneously.
Note: Be careful about using mutable objects in sets. In particular, if a mutable object changes to become equal to another set element, you have violated the contract. As a special case of this, a Set is not allowed to be an element of itself, without risking undefined behavior.

Since:

1.2

Author:

Original author unknown, Eric Blake (ebb9@email.byu.edu)

See Also:

LongCollection, AbstractLongSet

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`boolean`	`add(long o)` Adds the specified element to the set if it is not already present (optional operation).
`boolean`	`addAll(LongCollection c)` Adds all of the elements of the given collection to this set (optional operation).
`void`	`clear()` Removes all elements from this set (optional operation).
`boolean`	`contains(long o)` Returns true if the set contains the specified element.
`boolean`	`containsAll(LongCollection c)` Returns true if this set contains all elements in the specified collection.
`boolean`	`equals(java.lang.Object o)` Compares the specified object to this for equality.
`int`	`hashCode()` Returns the hash code for this set.
`boolean`	`isEmpty()` Returns true if the set contains no elements.
`LongIterator`	`iterator()` Returns an iterator over the set.
`boolean`	`remove(long o)` Removes the specified element from this set (optional operation).
`boolean`	`removeAll(LongCollection c)` Removes from this set all elements contained in the specified collection (optional operation).
`boolean`	`retainAll(LongCollection c)` Retains only the elements in this set that are also in the specified collection (optional operation).
`int`	`size()` Returns the number of elements in the set.
`long[]`	`toArray()` Returns an array containing the elements of this set.
`long[]`	`toArray(long[] a)` Returns an array containing the elements of this set, of the same runtime type of the argument.

- Method Detail
  - add
```
boolean add(long o)
```
    Adds the specified element to the set if it is not already present (optional operation). In particular, the comparison algorithm is o == null ? e == null : o.equals(e). Sets need not permit all values, and may document what exceptions will be thrown if a value is not permitted.
    
    Specified by:
    
    add in interface LongCollection
    
    Parameters:
    
    o - the object to add
    
    Returns:
    
    true if the object was not previously in the set
    
    Throws:
    
    java.lang.UnsupportedOperationException - if this operation is not allowed
    
    java.lang.ClassCastException - if the class of o prevents it from being added
    
    java.lang.IllegalArgumentException - if some aspect of o prevents it from being added
    
    java.lang.NullPointerException - if null is not permitted in this set
  - addAll
```
boolean addAll(LongCollection c)
```
    Adds all of the elements of the given collection to this set (optional operation). If the argument is also a Set, this returns the mathematical union of the two. The behavior is unspecified if the set is modified while this is taking place.
    
    Specified by:
    
    addAll in interface LongCollection
    
    Parameters:
    
    c - the collection to add
    
    Returns:
    
    true if the set changed as a result
    
    Throws:
    
    java.lang.UnsupportedOperationException - if this operation is not allowed
    
    java.lang.ClassCastException - if the class of an element prevents it from being added
    
    java.lang.IllegalArgumentException - if something about an element prevents it from being added
    
    java.lang.NullPointerException - if null is not permitted in this set, or if the argument c is null
    
    See Also:
    
    add(long)
  - clear
```
void clear()
```
    Removes all elements from this set (optional operation). This set will be empty afterwords, unless an exception occurs.
    
    Specified by:
    
    clear in interface LongCollection
    
    Throws:
    
    java.lang.UnsupportedOperationException - if this operation is not allowed
  - contains
```
boolean contains(long o)
```
    Returns true if the set contains the specified element. In other words, this looks for o == null ? e == null : o.equals(e).
    
    Specified by:
    
    contains in interface LongCollection
    
    Parameters:
    
    o - the object to look for
    
    Returns:
    
    true if it is found in the set
    
    Throws:
    
    java.lang.ClassCastException - if the type of o is not a valid type for this set.
    
    java.lang.NullPointerException - if o is null and this set doesn't support null values.
  - containsAll
```
boolean containsAll(LongCollection c)
```
    Returns true if this set contains all elements in the specified collection. If the argument is also a set, this is the subset relationship.
    
    Specified by:
    
    containsAll in interface LongCollection
    
    Parameters:
    
    c - the collection to check membership in
    
    Returns:
    
    true if all elements in this set are in c
    
    Throws:
    
    java.lang.NullPointerException - if c is null
    
    java.lang.ClassCastException - if the type of any element in c is not a valid type for this set.
    
    java.lang.NullPointerException - if some element of c is null and this set doesn't support null values.
    
    See Also:
    
    contains(long)
  - equals
```
boolean equals(java.lang.Object o)
```
    Compares the specified object to this for equality. For sets, the object must be a set, the two must have the same size, and every element in one must be in the other.
    
    Specified by:
    
    equals in interface LongCollection
    
    Overrides:
    
    equals in class java.lang.Object
    
    Parameters:
    
    o - the object to compare to
    
    Returns:
    
    true if it is an equal set
  - hashCode
```
int hashCode()
```
    Returns the hash code for this set. In order to satisfy the contract of equals, this is the sum of the hashcode of all elements in the set.
    
    Specified by:
    
    hashCode in interface LongCollection
    
    Overrides:
    
    hashCode in class java.lang.Object
    
    Returns:
    
    the sum of the hashcodes of all set elements
    
    See Also:
    
    equals(Object)
  - isEmpty
```
boolean isEmpty()
```
    Returns true if the set contains no elements.
    
    Specified by:
    
    isEmpty in interface LongCollection
    
    Returns:
    
    true if the set is empty
  - iterator
```
LongIterator iterator()
```
    Returns an iterator over the set. The iterator has no specific order, unless further specified.
    
    Specified by:
    
    iterator in interface LongCollection
    
    Specified by:
    
    iterator in interface LongIterable
    
    Returns:
    
    a set iterator
  - remove
```
boolean remove(long o)
```
    Removes the specified element from this set (optional operation). If an element e exists, o == null ? e == null : o.equals(e), it is removed from the set.
    
    Specified by:
    
    remove in interface LongCollection
    
    Parameters:
    
    o - the object to remove
    
    Returns:
    
    true if the set changed (an object was removed)
    
    Throws:
    
    java.lang.UnsupportedOperationException - if this operation is not allowed
    
    java.lang.ClassCastException - if the type of o is not a valid type for this set.
    
    java.lang.NullPointerException - if o is null and this set doesn't allow the removal of a null value.
  - removeAll
```
boolean removeAll(LongCollection c)
```
    Removes from this set all elements contained in the specified collection (optional operation). If the argument is a set, this returns the asymmetric set difference of the two sets.
    
    Specified by:
    
    removeAll in interface LongCollection
    
    Parameters:
    
    c - the collection to remove from this set
    
    Returns:
    
    true if this set changed as a result
    
    Throws:
    
    java.lang.UnsupportedOperationException - if this operation is not allowed
    
    java.lang.NullPointerException - if c is null
    
    java.lang.ClassCastException - if the type of any element in c is not a valid type for this set.
    
    java.lang.NullPointerException - if some element of c is null and this set doesn't support removing null values.
    
    See Also:
    
    remove(long)
  - retainAll
```
boolean retainAll(LongCollection c)
```
    Retains only the elements in this set that are also in the specified collection (optional operation). If the argument is also a set, this performs the intersection of the two sets.
    
    Specified by:
    
    retainAll in interface LongCollection
    
    Parameters:
    
    c - the collection to keep
    
    Returns:
    
    true if this set was modified
    
    Throws:
    
    java.lang.UnsupportedOperationException - if this operation is not allowed
    
    java.lang.NullPointerException - if c is null
    
    java.lang.ClassCastException - if the type of any element in c is not a valid type for this set.
    
    java.lang.NullPointerException - if some element of c is null and this set doesn't support retaining null values.
    
    See Also:
    
    remove(long)
  - size
```
int size()
```
    Returns the number of elements in the set. If there are more than Integer.MAX_VALUE mappings, return Integer.MAX_VALUE. This is the cardinality of the set.
    
    Specified by:
    
    size in interface LongCollection
    
    Returns:
    
    the number of elements
  - toArray
```
long[] toArray()
```
    Returns an array containing the elements of this set. If the set makes a guarantee about iteration order, the array has the same order. The array is distinct from the set; modifying one does not affect the other.
    
    Specified by:
    
    toArray in interface LongCollection
    
    Returns:
    
    an array of this set's elements
    
    See Also:
    
    toArray(long[])
  - toArray
```
long[] toArray(long[] a)
```
    Returns an array containing the elements of this set, of the same runtime type of the argument. If the given set is large enough, it is reused, and null is inserted in the first unused slot. Otherwise, reflection is used to build a new array. If the set makes a guarantee about iteration order, the array has the same order. The array is distinct from the set; modifying one does not affect the other.
    
    Specified by:
    
    toArray in interface LongCollection
    
    Parameters:
    
    a - the array to determine the return type; if it is big enough it is used and returned
    
    Returns:
    
    an array holding the elements of the set
    
    Throws:
    
    java.lang.ArrayStoreException - if the runtime type of a is not a supertype of all elements in the set
    
    java.lang.NullPointerException - if a is null
    
    See Also:
    
    toArray()

Interface LongSet

Method Summary

Method Detail

add

addAll

clear

contains

containsAll

equals

hashCode

isEmpty

iterator

remove

removeAll

retainAll

size

toArray

toArray