Class Pair<K,V>

java.lang.Object
org.apache.commons.math3.util.Pair<K,V>
Type Parameters:
K - Key type.
V - Value type.
Direct Known Subclasses:
PointValuePair, PointValuePair, PointVectorValuePair, PointVectorValuePair
public class Pair<K,V> extends Object
Generic pair.
Although the instances of this class are immutable, it is impossible to ensure that the references passed to the constructor will not be modified by the caller.
Since:
3.0

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private final K
    key
    Key.
    private final V
    value
    Value.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Pair(K k, V v)
    Create an entry representing a mapping from the specified key to the specified value.
    Pair(Pair<? extends K, ? extends V> entry)
    Create an entry representing the same mapping as the specified entry.

  • Method Summary

    Modifier and Type
    Method
    Description
    static <K,V> Pair<K,V>
    create(K k, V v)
    Convenience factory method that calls the constructor.
    boolean
    equals(Object o)
    Compare the specified object with this entry for equality.
    K
    getFirst()
    Get the first element of the pair.
    K
    getKey()
    Get the key.
    V
    getSecond()
    Get the second element of the pair.
    V
    getValue()
    Get the value.
    int
    hashCode()
    Compute a hash code.
    String
    toString()

    Methods inherited from class Object

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

  • Field Details

    • key

      private final K key
      Key.

    • value

      private final V value
      Value.

  • Constructor Details

    • Pair

      public Pair(K k, V v)
      Create an entry representing a mapping from the specified key to the specified value.
      Parameters:
      k - Key (first element of the pair).
      v - Value (second element of the pair).

    • Pair

      public Pair(Pair<? extends K, ? extends V> entry)
      Create an entry representing the same mapping as the specified entry.
      Parameters:
      entry - Entry to copy.

  • Method Details

    • getKey

      public K getKey()
      Get the key.
      Returns:
      the key (first element of the pair).

    • getValue

      public V getValue()
      Get the value.
      Returns:
      the value (second element of the pair).

    • getFirst

      public K getFirst()
      Get the first element of the pair.
      Returns:
      the first element of the pair.
      Since:
      3.1

    • getSecond

      public V getSecond()
      Get the second element of the pair.
      Returns:
      the second element of the pair.
      Since:
      3.1

    • equals

      public boolean equals(Object o)
      Compare the specified object with this entry for equality.
      Overrides:
      equals in class Object
      Parameters:
      o - Object.
      Returns:
      true if the given object is also a map entry and the two entries represent the same mapping.

    • hashCode

      public int hashCode()
      Compute a hash code.
      Overrides:
      hashCode in class Object
      Returns:
      the hash code value.

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • create

      public static <K,V> Pair<K,V> create(K k, V v)
      Convenience factory method that calls the constructor.
      Type Parameters:
      K - the key type
      V - the value type
      Parameters:
      k - First element of the pair.
      v - Second element of the pair.
      Returns:
      a new Pair containing k and v.
      Since:
      3.3