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Java Hashtable putAll() Method with Example

Hashtable Class putAll() method: Here, we are going to learn about the putAll() method of Hashtable Class with its syntax and example.
Submitted by Preeti Jain, on February 17, 2020

Hashtable Class putAll() method

• putAll() method is available in java.util package.
• putAll() method is used to copy all the mappings that exist from the given Map to this Hashtable.
• putAll() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
• putAll() method does not throw an exception at the time of copying mappings.

Syntax:

    public void putAll(Map m);

Parameter(s):

• Map m – the mappings to be exists in this Map (m).

Return value:

The return type of the method is void, it returns nothing.

Example:

// Java program to demonstrate the example 
// of void putAll(Map m) method of Hashtable 

import java.util.*;

public class PutAllOfHashtable {
    public static void main(String[] args) {
        //Instantiate a linked hashmap
        //and hashtable object  
        Map lhm = new LinkedHashMap();
        Hashtable ht = new Hashtable();

        // By using put() method is to
        // add the linked values in an
        // linked hashmap lhm
        lhm.put(10, "C");
        lhm.put(20, "C++");
        lhm.put(30, "JAVA");
        lhm.put(40, "PHP");
        lhm.put(50, "SFDC");

        // Display linked hashmap
        System.out.println("lhm: " + lhm);

        // By using putAll() method is to 
        // copy all of the key-value pairs
        // exists in this linked hashmap and
        // paste it into this Hashtable

        ht.putAll(lhm);

        // Display Hashtable
        System.out.println("ht.putAll(lhm): " + ht);
    }
}

Output

lhm: {10=C, 20=C++, 30=JAVA, 40=PHP, 50=SFDC}
ht.putAll(lhm): {10=C, 20=C++, 30=JAVA, 40=PHP, 50=SFDC}