- Java.util Package Classes
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- Java.util - ArrayDeque
- Java.util - ArrayList
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- Java.util - BitSet
- Java.util - Calendar
- Java.util - Collections
- Java.util - Currency
- Java.util - Date
- Java.util - Dictionary
- Java.util - EnumMap
- Java.util - EnumSet
- Java.util - Formatter
- Java.util - GregorianCalendar
- Java.util - HashMap
- Java.util - HashSet
- Java.util - Hashtable
- Java.util - IdentityHashMap
- Java.util - LinkedHashMap
- Java.util - LinkedHashSet
- Java.util - LinkedList
- Java.util - ListResourceBundle
- Java.util - Locale
- Java.util - Observable
- Java.util - PriorityQueue
- Java.util - Properties
- Java.util - PropertyPermission
- Java.util - PropertyResourceBundle
- Java.util - Random
- Java.util - ResourceBundle
- Java.util - ResourceBundle.Control
- Java.util - Scanner
- Java.util - ServiceLoader
- Java.util - SimpleTimeZone
- Java.util - Stack
- Java.util - StringTokenizer
- Java.util - Timer
- Java.util - TimerTask
- Java.util - TimeZone
- Java.util - TreeMap
- Java.util - TreeSet
- Java.util - UUID
- Java.util - Vector
- Java.util - WeakHashMap
- Java.util Package Extras
- Java.util - Interfaces
- Java.util - Exceptions
- Java.util - Enumerations
- Java.util Useful Resources
- Java.util - Useful Resources
- Java.util - Discussion
Java Dictionary remove() Method
Description
The Java Dictionary remove(Object key) method removes the value and it's corresponding key from this dictionary.
Declaration
Following is the declaration for java.util.Dictionary.remove() method
public abstract V remove(Object key)
Parameters
key − the key to be removed.
Return Value
This method returns the value to which the key had been mapped, or null if the key did not have a mapping.
Exception
NullPointerException − if key is null.
Removing a Mapping of Key-Value to Dictionary of Integer,Integer Pair Example
The following example shows the usage of Java Dictionary remove(Object) method. We're creating a dictionary instance using Hashtable object of Integer, Integer pairs. Then we've added few elements to it. Then a element is removed using remove(Object) method. An enumeration is retrieved using elements() method and enumeration is then iterated to print the elements of the dictionary.
package com.tutorialspoint; import java.util.Enumeration; 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<>(); // add 3 elements dictionary.put(1, 1); dictionary.put(2, 2); dictionary.put(3, 3); // remove one element dictionary.remove(2); Enumeration<Integer> enumeration = dictionary.elements(); while(enumeration.hasMoreElements()) { System.out.println(enumeration.nextElement()); } } }
Output
Let us compile and run the above program, this will produce the following result −
3 1
Removing a Mapping of Key-Value to Dictionary of Integer,String Pair Example
The following example shows the usage of Java Dictionary remove(Object) method. We're creating a dictionary instance using Hashtable object of Integer, String pairs. Then we've added few elements to it. Then a element is removed using remove(Object) method. An enumeration is retrieved using elements() method and enumeration is then iterated to print the elements of the dictionary.
package com.tutorialspoint; import java.util.Enumeration; 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<>(); // add 2 elements dictionary.put(1, "One"); dictionary.put(2, "Two"); dictionary.put(3, "Three"); // remove one element dictionary.remove(2); Enumeration<String> enumeration = dictionary.elements(); while(enumeration.hasMoreElements()) { System.out.println(enumeration.nextElement()); } } }
Output
Let us compile and run the above program, this will produce the following result −
Three One
Removing a Mapping of Key-Value to Dictionary of Integer,Object Pair Example
The following example shows the usage of Java Dictionary remove(Object) method. We're creating a dictionary instance using Hashtable object of Integer, Student pairs. Then we've added few elements to it. Then a element is removed using remove(Object) method. An enumeration is retrieved using elements() method and enumeration is then iterated to print the elements of the dictionary.
package com.tutorialspoint; import java.util.Enumeration; 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<>(); // add 2 elements dictionary.put(1, new Student(1, "Julie")); dictionary.put(2, new Student(2, "Robert")); dictionary.put(3, new Student(3, "Adam")); // remove one element dictionary.remove(2); Enumeration<Student> enumeration = dictionary.elements(); while(enumeration.hasMoreElements()) { System.out.println(enumeration.nextElement()); } } } 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 −
[ 3, Adam ] [ 1, Julie ]
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