Java: Check whether a map contains key-value mappings (empty) or not
Java Collection, HashMap Exercises: Exercise-5 with Solution
Write a Java program to check whether a map contains key-value mappings (empty) or not.
Sample Solution:-
Java Code:
import java.util.*;
public class Example5 {
public static void main(String args[]) {
HashMap <Integer,String> hash_map = new HashMap <Integer,String> ();
hash_map.put(1, "Red");
hash_map.put(2, "Green");
hash_map.put(3, "Black");
hash_map.put(4, "White");
hash_map.put(5, "Blue");
// check if map is empty
boolean result = hash_map.isEmpty();
// check the result
System.out.println("Is hash map empty: " + result);
// Removing all the elements from the linked map
hash_map.clear();
// check if map is empty
result = hash_map.isEmpty();
// check the result
System.out.println("Is hash map empty: " + result);
}
}
Sample Output:
Is hash map empty: false Is hash map empty: true
Java Code Editor:
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