Question

I need help with the following question please in JAVA code.

1. Hash code is used to “encode” general keys into integers. One approach of creating a hash code is to use Java's hashCode() method. The hashCode() method is implemented in the Object class and therefore each class in Java inherits it. The hash code provides a numeric representation of an object (this is somewhat similar to the toString method that gives a text representation of an object).

1. Write a program to show the hash code of the following.

                Integer 2018,

                String “2018”,

                StringBuffer “2018”,

                ArrayList with first element is Integer 2018.

2. Verify that different objects might have the same hashcode. For example, show the hashcode for the strings “Aa” and “BB”.

Answer 1

Answer 1:

import java.util.ArrayList;

public class HashTest {
public static void main(String[] args) {
   // creating the given objects
   Integer i = new Integer(2018);
   String str="2018";
   StringBuffer sb = new StringBuffer("2018");
   ArrayList al = new ArrayList();
   al.add(i);
   // printing the hascodes
   System.out.println(i.hashCode());
   System.out.println(str.hashCode());
   System.out.println(sb.hashCode());
   System.out.println(al.hashCode());
  
}
}

Answer b:

public class HashTest {
public static void main(String[] args) {
  
   String str="Aa";
   String str2="BB";
   System.out.println(str.hashCode());
   System.out.println(str2.hashCode());
  
}
}