Map size() Method in Java With Examples

Map size() method in Java is used to get the total number entries i.e, key-value pair. So this method is useful when you want total entries present on the map. If the map contains more than Integer.MAX_VALUE elements returnInteger.MAX_VALUE

Syntax:

int size();

Parameter: This method does not take any parameter.

Return value: This method returns the number of key-value mappings in this map.

Example 1: For non-generic input

Java

// Java program to illustrate
// the Map size() Method
import java.util.*;

public class MapSizeExample {

      // Main Method
    public static void main(String[] args)
    {
        Map map = new HashMap();

          // Adding key-values
        map.put(1, "Amit");
        map.put(5, "Rahul");
        map.put(2, "Jai");
        map.put(6, "Amit");

          // using the method
        System.out.println("Size of the map is : "
                           + map.size());
    }
}

Output:

Size of the map is : 4

Example 2: For Generic Input

Java

// Java program to illustrate
// the Map size() Method
import java.util.*;

class MapSizeExample {

    // Main Method
    public static void main(String[] args)
    {

        Map<Integer, String> map
            = new HashMap<Integer, String>();

        map.put(1, "one");
        map.put(2, "two");
        map.put(3, "three");
        map.put(4, "four");

        // using the method
        System.out.println("Size of map is :"
                           + map.size());
    }
}

Output:

Size of the map is : 4