- 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
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- 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 TreeMap lastKey() Method
Description
The Java TreeMap lastKey() method is used to return the last (highest) key currently in this map.
Declaration
Following is the declaration for java.util.TreeMap.lastKey() method.
public K lastKey()
Parameters
NA
Return Value
The method call returns the last (highest) key currently in this map.
Exception
NoSuchElementException − This exception is thrown if this map is empty.
Getting Last Key from a TreeMap of Integer,Integer Pair Example
The following example shows the usage of Java TreeMap lastKey() method to get the last or highest key present in the map. We've created a TreeMap object of Integer,Integer pairs. Then few entries are added, and using lastKey() we're printing the last key.
package com.tutorialspoint; import java.util.TreeMap; public class TreeMapDemo { public static void main(String[] args) { // creating tree map TreeMap<Integer, Integer> treemap = new TreeMap<>(); // populating tree map treemap.put(2, 2); treemap.put(1, 1); treemap.put(3, 3); treemap.put(6, 6); treemap.put(5, 5); // getting the last key System.out.println("Checking last key"); System.out.println("Value is: "+ treemap.lastKey()); } }
Output
Let us compile and run the above program, this will produce the following result.
Checking last key Value is: 6
Getting Last Key from a TreeMap of Integer,String Pair Example
The following example shows the usage of Java TreeMap lastKey() method to get the last or highest key present in the map. We've created a TreeMap object of Integer,String pairs. Then few entries are added, and using lastKey() we're printing the last key.
package com.tutorialspoint; import java.util.TreeMap; public class TreeMapDemo { public static void main(String[] args) { // creating tree map TreeMap<Integer, String> treemap = new TreeMap<>(); // populating tree map treemap.put(2, "two"); treemap.put(1, "one"); treemap.put(3, "three"); treemap.put(6, "six"); treemap.put(5, "five"); // getting the last key System.out.println("Checking last key"); System.out.println("Value is: "+ treemap.lastKey()); } }
Output
Let us compile and run the above program, this will produce the following result.
Checking last key Value is: 6
Getting Last Key from a TreeMap of Integer,Object Pair Example
The following example shows the usage of Java TreeMap lastKey() method to get the last or highest key present in the map. We've created a TreeMap object of Integer,Student pairs. Then few entries are added, and using lastKey() we're printing the last key.
package com.tutorialspoint; import java.util.TreeMap; public class TreeMapDemo { public static void main(String[] args) { // creating tree map TreeMap<Integer, Student> treemap = new TreeMap<>(); // populating tree map treemap.put(2, new Student(2, "Robert")); treemap.put(1, new Student(1, "Julie")); treemap.put(3, new Student(3, "Adam")); treemap.put(6, new Student(5, "Julia")); treemap.put(5, new Student(5, "Tom")); // getting the last key System.out.println("Checking last key"); System.out.println("Value is: "+ treemap.lastKey()); } } 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 + " ]"; } @Override public boolean equals(Object obj) { if(obj == null) return false; Student s = (Student)obj; return this.rollNo == s.rollNo && this.name.equalsIgnoreCase(s.name); } }
Output
Let us compile and run the above program, this will produce the following result.
Checking last key Value is: 6
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