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Generics in Java, Standard Values

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By User



Ok, so I was reading the Java online tutorial for generics and I found this:







E - Element (used extensively by the Java Collections Framework)

K - Key

N - Number

T - Type

V - Value

S,U,V etc. - 2nd, 3rd, 4th types







I have seen a lot of methods in Java use the "E" notation but I was looking for a method that uses the "K", key notation. Anyone can help please?


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Comments

  1. Tips For AllFebruary 24, 2012 at 7:31 AM

    Theres no real need to use K, V, E, T etc in your own classes but they are nice standards.

    K and V for example are used by Map. A good example of K and V is a HashMap!

    HashMap<K, V> hm = new HashMap<K, V>();


    And implementing:

    HashMap<Integer, String> hm = new HashMap<Integer, String>();

    ReplyDelete
  2. Tips For AllFebruary 24, 2012 at 7:31 AM

    The HashMap (java.util.HashMap<K,V>) uses it for example.

    ReplyDelete
  3. Tips For AllFebruary 24, 2012 at 7:31 AM

    Pretty sure a Map K uses and V

    public interface Map<K,V>

    ReplyDelete
  4. Tips For AllFebruary 24, 2012 at 7:31 AM

    java.util.Map is defined:

    public interface Map<K, V> { ... }

    ReplyDelete

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