Use the remove() method to remove a key from TreeMap.
Let us first create a TreeMap and add some elements −
TreeMap<Integer,String> m = new TreeMap<Integer,String>(); m.put(1,"India"); m.put(2,"US"); m.put(3,"Australia"); m.put(4,"Netherlands"); m.put(5,"Canada");
Let us remove a key now. Here, we are removing key 3 now −
m.remove(3)
The following is an example to remove a key from TreeMap −
import java.util.*; public class Demo { public static void main(String args[]) { TreeMap<Integer,String> m = new TreeMap<Integer,String>(); m.put(1,"India"); m.put(2,"US"); m.put(3,"Australia"); m.put(4,"Netherlands"); m.put(5,"Canada"); System.out.println("TreeMap Elements = "+m); System.out.println("Removing a Key = "+m.remove(3)); System.out.println("Updated TreeMap Elements = "+m); } }
TreeMap Elements = {1=India, 2=US, 3=Australia, 4=Netherlands, 5=Canada} Removing a Key = Australia Updated TreeMap Elements = {1=India, 2=US, 4=Netherlands, 5=Canada}