- Java.util Package Classes
- Java.util - Home
- Java.util - ArrayDeque
- Java.util - ArrayList
- Java.util - Arrays
- 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 TreeMap size() Method
Description
The Java TreeMap size() method is used to return the number of key-value mappings in this map.
Declaration
Following is the declaration for java.util.TreeMap.size() method.
public int size()
Parameters
NA
Return Value
The method call returns the number of key-value mappings in this map.
Exception
NA
Getting Size of a TreeMap of Integer,Integer Pair Example
The following example shows the usage of Java TreeMap size() method to get the total key-value mappings present in the map. We've created a TreeMap object of Integer,Integer pairs. Then few entries are added, and using size() we're printing a count of key-value mappings.
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 size of the map System.out.println("Size of the map: "+treemap.size()); } }
Output
Let us compile and run the above program, this will produce the following result.
Size of the map: 5
Getting Size of a TreeMap of Integer,String Pair Example
The following example shows the usage of Java TreeMap size() method to get the total key-value mappings present in the map. We've created a TreeMap object of Integer,String pairs. Then few entries are added, and using size() we're printing a count of key-value mappings.
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 size of the map System.out.println("Size of the map: "+treemap.size()); } }
Output
Let us compile and run the above program, this will produce the following result.
Size of the map: 5
Getting Size of a TreeMap of Integer,Object Pair Example
The following example shows the usage of Java TreeMap size() method to get the total key-value mappings present in the map. We've created a TreeMap object of Integer,Student pairs. Then few entries are added, and using size() we're printing a count of key-value mappings.
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(6, "Julia")); treemap.put(5, new Student(5, "Tom")); // getting size of the map System.out.println("Size of the map: "+treemap.size()); } } 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.
Size of the map: 5
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