Java Dictionary isEmpty() Method

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Description

The Java Dictionary.isEmpty() method check if this dictionary has no keys to value.

Declaration

Following is the declaration for java.util.Dictionary.isEmpty() method

public abstract boolean isEmpty()

Parameters

NA

Return Value

This method returns true if this dictionary has no keys to values; false otherwise.

Exception

NA

Checking Dictionary of Integer,Integer Pair to be Empty Example

The following example shows the usage of Java Dictionary isEmpty() method. We're creating a dictionary instance using Hashtable object of Integer, Integer pairs. We're checking status of dictionary using isEmpty() method and printing the result. Then we've added few elements to it and status of dictionary using isEmpty() method and print the result.

package com.tutorialspoint;

import java.util.Dictionary;
import java.util.Hashtable;

public class DictionaryDemo {
   public static void main(String[] args) {

      // create a new hashtable
      Dictionary<Integer, Integer> dictionary = new Hashtable<>();
      System.out.println(dictionary.isEmpty());

      // add 2 elements
      dictionary.put(1, 1);
      dictionary.put(2, 2);

      System.out.println(dictionary.isEmpty());
   }
}

Output

Let us compile and run the above program, this will produce the following result −

true
false

Checking Dictionary of Integer,String Pair to be Empty Example

The following example shows the usage of Java Dictionary isEmpty() method. We're creating a dictionary instance using Hashtable object of Integer, String pairs. We're checking status of dictionary using isEmpty() method and printing the result. Then we've added few elements to it and status of dictionary using isEmpty() method and print the result.

package com.tutorialspoint;

import java.util.Dictionary;
import java.util.Hashtable;

public class DictionaryDemo {
   public static void main(String[] args) {

      // create a new hashtable
      Dictionary<Integer, String> dictionary = new Hashtable<>();
      System.out.println(dictionary.isEmpty());

      // add 2 elements
      dictionary.put(1, "One");
      dictionary.put(2, "Two");
      System.out.println(dictionary.isEmpty());
   }
}

Output

Let us compile and run the above program, this will produce the following result −

true
false

Checking Dictionary of Integer,Object Pair to be Empty Example

The following example shows the usage of Java Dictionary isEmpty() method. We're creating a dictionary instance using Hashtable object of Integer, Student pairs. We're checking status of dictionary using isEmpty() method and printing the result. Then we've added few elements to it and status of dictionary using isEmpty() method and print the result.

package com.tutorialspoint;

import java.util.Dictionary;
import java.util.Hashtable;

public class DictionaryDemo {
   public static void main(String[] args) {

      // create a new hashtable
      Dictionary<Integer, Student> dictionary = new Hashtable<>();
      System.out.println(dictionary.isEmpty());

      // add 2 elements
      dictionary.put(1, new Student(1, "Julie"));
      dictionary.put(2, new Student(2, "Robert"));

      System.out.println(dictionary.isEmpty());
   }
}
class Student {
   int rollNo;
   String name;

   Student(int rollNo, String name){
      this.rollNo = rollNo;
      this.name = name;
   }

   @Override
   public String toString() {
      return "[ " + this.rollNo + ", " + this.name + " ]";
   }
}

Output

Let us compile and run the above program, this will produce the following result −

true
false