Java Collection Tutorial - Java TreeMap.containsKey(Object key)


TreeMap.containsKey(Object key) has the following syntax.

public boolean containsKey(Object key)


In the following code shows how to use TreeMap.containsKey(Object key) method.

/*from  w  ww.j  a v  a 2 s  .  c  om*/
import java.util.NavigableMap;
import java.util.TreeMap;

public class Main {
   public static void main(String[] args) {
      NavigableMap<Integer, String>  treemap = new TreeMap<Integer, String> ();
      // populating tree map
      treemap.put(2, "two");
      treemap.put(1, "one");
      treemap.put(3, "three");
      treemap.put(6, "six");
      treemap.put(5, "from");
      System.out.println("Checking key value 6");
      System.out.println("Value for key 6 exists: "+ treemap.containsKey(6));

The code above generates the following result.