Java Collection, HashMap Exercises: Count the number of key-value (size) mappings in a map
Java Collection, HashMap Exercises: Exercise-2 with Solution
Write a Java program to count the number of key-value (size) mappings in a map.
Sample Solution:-
Java Code:
import java.util.*;
public class Example2 {
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");
System.out.println("Size of the hash map: "+hash_map.size());
}
}
Sample Output:
Size of the hash map: 5
Java Code Editor:
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Previous: Associate the specified value with the specified key in a HashMap.
Next: Copy all of the mappings from the specified map to another map.
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Java: Tips of the Day
How to sort an ArrayList?
Collections.sort(testList); Collections.reverse(testList);
That will do what you want. Remember to import Collections though!
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