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 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 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