LinkedHashMap and HashMap

[Sricharan Modali]

Iam confused by the output of the following program.

import java.util.*;
class GFC111 {
  public static void main (String[] args) {
    Object m = new LinkedHashMap();
    System.out.print((m instanceof Collection)+",");
    System.out.print((m instanceof Map)+",");
    System.out.print(m instanceof HashMap);
}}  

the output is false, true, true
How can an this m instanceof HashMap be true? They are the same level isnt it?

[Richard Quist]

LinkedHashMap extends HashMap, therefore LinkedHashMap IS-A HashMap and instanceof returns true.
Here's the java api doc page for the class.
Hope that helps.

[Vineela Devi]

Hi Sricharan,
HashMap is the superclass of LinkedHashMap and so, the code
m instanceof HashMap results in true.
Regards
Vineela