Add elements in HashTable

We can use put() and putAll() methods of HashTable to add elements to HashTable

Object put(Object key, Object value);


Associates the specified value with the specified key in this map.

This method is used to add single key-value pair to the HashTable

Example

  1. import java.util.*;
  2. public class HashTablePutExample {
  3. public static void main(String args[]) {
  4.  Hashtable<Integer,String> hashTable =new Hashtable<Integer,String>();
  5.  
  6.       hashTable.put(1, "One");
  7.       hashTable.put(2, "Two");
  8.       hashTable.put(3, "Three");
  9.      
  10.  
  11. System.out.println(hashTable);
  12.  
  13. }
  14. }
import java.util.*;
public class HashTablePutExample {
public static void main(String args[]) {
 Hashtable<Integer,String> hashTable =new Hashtable<Integer,String>(); 

      hashTable.put(1, "One");
      hashTable.put(2, "Two");
      hashTable.put(3, "Three");
      

System.out.println(hashTable);

}
}


void putAll(Map m);


Copies all of the mappings from the specified map to this hash table.

This method is used to add all key-value pairs from another Map to this HashTable

Example

  1. import java.util.*;
  2. public class HashTablePutAllExample {
  3. public static void main(String args[]) {
  4.  
  5.  Hashtable<Integer,String> hashTable=new Hashtable<Integer,String>();
  6.  
  7.       hashTable.put(1, "One");
  8.       hashTable.put(2, "Two");
  9.       hashTable.put(3, "Three");
  10.      
  11. Hashtable<Integer,String> hashTable1=new Hashtable<Integer,String>();
  12. hashTable1.put(4, "Four");
  13.       hashTable1.put(5, "Five");
  14.  
  15. hashTable.putAll(hashTable1);
  16. System.out.println(hashTable);
  17.  
  18. }
  19. }
import java.util.*;
public class HashTablePutAllExample {
public static void main(String args[]) {

 Hashtable<Integer,String> hashTable=new Hashtable<Integer,String>();

      hashTable.put(1, "One");
      hashTable.put(2, "Two");
      hashTable.put(3, "Three");
      
Hashtable<Integer,String> hashTable1=new Hashtable<Integer,String>();
hashTable1.put(4, "Four");
      hashTable1.put(5, "Five");

hashTable.putAll(hashTable1);
System.out.println(hashTable);

}
}
Note : We can see that hashTable1 has 2 key-value pairs and these 2 are added to main HashTable using putAll() 
             method

About the Author

Karibasappa G C (KB)
Founder of javainsimpleway.com
I love Java and open source technologies and very much passionate about software development.
I like to share my knowledge with others especially on technology 🙂
I have given all the examples as simple as possible to understand for the beginners.
All the code posted on my blog is developed,compiled and tested in my development environment.
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