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








Syntax

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

public boolean containsKey(Object key)

Example

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

/* w  w  w. j  a  v  a2  s. c om*/
import java.util.Map;
import java.util.WeakHashMap;

public class Main {
   public static void main(String[] args) { 
      Map<String, String>  weakHashMap = new WeakHashMap<String, String> ();
      
            
      weakHashMap.put("1", "first");
      weakHashMap.put("2", "two");
      weakHashMap.put("3", "from java2s.com");
      
      // check key value 
      System.out.println("Checking value for key 1");
      System.out.println(weakHashMap.containsKey("1"));
   }    
}

The code above generates the following result.