SortedMap putAll() method in Java with Examples

The putAll() method of SortedMap interface in Java is used to copy all of the mappings from the specified SortedMap to this SortedMap.

Syntax: 

void putAll(Map m)

Parameters: This method has the only argument map m which contains key-value mappings to be copied to given SortedMap.

Returns: This method returns previous value associated with the key if present, else return -1.

Note: The putAll() method in SortedMap is inherited from the Map interface in Java.

Below programs illustrate the implementation of int putAll() method:

Program 1:

Java

// Java code to show the implementation of
// putAll method in SortedMap interface

import java.util.*;

public class GfG {

    // Driver code
    public static void main(String[] args)
    {

        // Initializing a SortedMap
        SortedMap<Integer, String> map
            = new TreeMap<>();

        map.put(1, "One");
        map.put(3, "Three");
        map.put(5, "Five");
        map.put(7, "Seven");
        map.put(9, "Nine");
        System.out.println(map);

        SortedMap<Integer, String> mp
            = new TreeMap<>();

        mp.put(10, "Ten");
        mp.put(30, "Thirty");
        mp.put(50, "Fifty");

        map.putAll(mp);

        System.out.println(map);
    }
}

Output:

{1=One, 3=Three, 5=Five, 7=Seven, 9=Nine}
{1=One, 3=Three, 5=Five, 7=Seven, 9=Nine, 10=Ten, 30=Thirty, 50=Fifty}

Program 2: Below is the code to show implementation of putAll(). 

Java

// Java code to show the implementation of
// putAll method in SortedMap interface

import java.util.*;
public class GfG {

    // Driver code
    public static void main(String[] args)
    {

        // Initializing a SortedMap
        SortedMap<String, String> map
            = new TreeMap<>();

        map.put("1", "One");
        map.put("3", "Three");
        map.put("5", "Five");
        map.put("7", "Seven");
        map.put("9", "Nine");
        System.out.println(map);

        SortedMap<String, String> mp
            = new TreeMap<>();

        mp.put("10", "Ten");
        mp.put("30", "Thirty");
        mp.put("50", "Fifty");

        map.putAll(mp);

        System.out.println(map);
    }
}

Output:

{1=One, 3=Three, 5=Five, 7=Seven, 9=Nine}
{1=One, 10=Ten, 3=Three, 30=Thirty, 5=Five, 50=Fifty, 7=Seven, 9=Nine}

Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Map.html#put(K, %20V)