Check if a particular key exists in Java TreeMap example

/*
  Check if a particular key exists in Java TreeMap example
  This Java Example shows how to check if TreeMap object contains a particular
  key using containsKey method of TreeMap class.
*/
 
import java.util.TreeMap;
 
public class CheckKeyOfTreeMapExample {
 
  public static void main(String[] args) {
 
    //create TreeMap object
    TreeMap treeMap = new TreeMap();
 
    //add key value pairs to TreeMap
    treeMap.put("1","One");
    treeMap.put("2","Two");
    treeMap.put("3","Three");
 
    /*
      To check whether a particular key exists in TreeMap use
      boolean containsKey(Object key) method of TreeMap class.
      It returns true if the TreeMap contains mapping for specified key
      otherwise false.
    */
 
    boolean blnExists = treeMap.containsKey("1");
    System.out.println("1 exists in TreeMap ? : " + blnExists);
  }
}
 
/*
Output would be
1 exists in TreeMap ? : true
*/