Home » Java programming language

Java WeakHashMap size() Method with Example

WeakHashMap Class size() method: Here, we are going to learn about the size() method of WeakHashMap Class with its syntax and example.
Submitted by Preeti Jain, on February 23, 2020

WeakHashMap Class size() method

• size() method is available in java.util package.
• size() method is used to get the number of key-value pairs that exist in this map.
• size() 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.
• size() method does not throw an exception at the time of returning the size of this map.

Syntax:

    public int size();

Parameter(s):

• It does not accept any parameter.

Return value:

The return type of the method is int, it returns the cardinality (i.e. the number of key-value pair exists) of this map.

Example:

// Java program to demonstrate the example 
// of int size() method of WeakHashMap 

import java.util.*;

public class SizeOfWeakHashMap {
    public static void main(String[] args) {
        // Instantiates a WeakHashMap object
        Map < Integer, String > map = new WeakHashMap < Integer, String > ();

        // By using put() method is to add
        // key-value pairs in a WeakHashMap
        map.put(10, "C");
        map.put(20, "C++");
        map.put(50, "JAVA");
        map.put(40, "PHP");
        map.put(30, "SFDC");

        //Display WeakHashMap
        System.out.println("WeakHashMap: " + map);

        // By using size() method is to return
        // the size of this WeakHashMap
        int size = map.size();

        // Display size
        System.out.print("map.size(): " + size);
    }
}

Output

WeakHashMap: {30=SFDC, 40=PHP, 10=C, 20=C++, 50=JAVA}
map.size(): 5