With this example we are going to demonstrate how to get the size of a TreeMap, that is the number of key value pairs that the TreeMap contains. In short, to get the size of a TreeMap you should:
- Create a new TreeMap.
- Populate the map with elements, with
put(K key, V value)API method of TreeMap. - Invoke
size()API method of TreeMap. The method returns the number of key value pairs stored in the TreeMap.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core;
import java.util.TreeMap;
public class SizeTreeMap {
public static void main(String[] args) {
// Create a TreeMap and populate it with elements
TreeMap treeMap = new TreeMap();
treeMap.put("key_1","element_1");
treeMap.put("key_3","element_3");
treeMap.put("key_2","element_2");
treeMap.put("key_4","element_4");
treeMap.put("key_5","element_5");
// int size() operation returns the number of key value pairs stored in TreeMap
System.out.println("Size of TreeMap : " + treeMap.size());
}
}
Output:
Size of TreeMap : 5
This was an example of how to get the size of a TreeMap in Java.
