The isEmpty() method of Dictionary Class checks whether this dictionary has any key-value mappings or not. The function returns TRUE only if there is no entry in this dictionary.
Syntax:
public abstract boolean isEmpty()
Return Value: The function returns TRUE if the dictionary is empty and FALSE otherwise.
Exception: The function throws no exception.
Below programs illustrate the use of Dictionary.isEmpty() method:
Program 1:
// Java Program to illustrate// Dictionary.isEmpty() method import java.util.*; class GFG { public static void main(String[] args) { // Create a new hashtable Dictionary<Integer, String> d = new Hashtable<Integer, String>(); // Insert elements in the hashtable d.put(1, "Geeks"); d.put(2, "for"); d.put(3, "Geeks"); // Print the Dictionary System.out.println("\nDictionary: " + d); // check if this dictionary is empty // using isEmpty() method if (d.isEmpty()) { System.out.println("Dictionary " + "is empty"); } else System.out.println("Dictionary " + "is not empty"); }} |
Output:
Dictionary: {3=Geeks, 2=for, 1=Geeks}
Dictionary is not empty
Program 2:
// Java Program to illustrate// Dictionary.isEmpty() method import java.util.*; class GFG { public static void main(String[] args) { // Create a new hashtable Dictionary<String, String> d = new Hashtable<String, String>(); // Print the Dictionary System.out.println("\nDictionary: " + d); // check if this dictionary is empty // using isEmpty() method if (d.isEmpty()) { System.out.println("Dictionary " + "is empty"); } else System.out.println("Dictionary " + "is not empty"); // Insert elements in the hashtable d.put("a", "GFG"); d.put("b", "gfg"); // Print the Dictionary System.out.println("\nDictionary: " + d); // check if this dictionary is empty // using isEmpty() method if (d.isEmpty()) { System.out.println("Dictionary " + "is empty"); } else System.out.println("Dictionary " + "is not empty"); // Remove elements in the hashtable d.remove("a"); d.remove("b"); // Print the Dictionary System.out.println("\nDictionary: " + d); // check if this dictionary is empty // using isEmpty() method if (d.isEmpty()) { System.out.println("Dictionary " + "is empty"); } else System.out.println("Dictionary " + "is not empty"); }} |
Output:
Dictionary: {}
Dictionary is empty
Dictionary: {b=gfg, a=GFG}
Dictionary is not empty
Dictionary: {}
Dictionary is empty
Reference:https://docs.oracle.com/javase/7/docs/api/java/util/Dictionary.html#isEmpty()
