ConcurrentSkipListMap containsKey() method in Java with Examples

The containsKey() method of java.util.concurrent.ConcurrentSkipListMap is an in-built function in Java which returns a true boolean value if the specified element is present in this map otherwise it returns false.

Syntax:

public boolean containsKey(Object ob)

Parameter: The function accepts a single mandatory parameter ob which specifies the key whose presence in this map is to be tested.

Return Value: The function returns true if this map contains a mapping for the specified key.

Below programs illustrate the above method:

Program 1:

// Java Program Demonstrate containsKey()
// method of ConcurrentSkipListMap

import java.util.concurrent.*;

class GFG {
    public static void main(String[] args)
    {

        // Initializing the map
        ConcurrentSkipListMap<Integer, Integer>
            mpp = new ConcurrentSkipListMap<Integer,
                                            Integer>();

        // Adding elements to this map
        for (int i = 1; i <= 5; i++)
            mpp.put(i, i);

        // Checks if 9 is present in the map
        if (mpp.containsKey(9))
            System.out.println("9 is present"
                               + " in the mpp.");
        else
            System.out.println("9 is not present"
                               + " in the mpp.");
    }
}

Program 2:

// Java Program Demonstrate containsKey()
// method of ConcurrentSkipListMap

import java.util.concurrent.*;

class GFG {
    public static void main(String[] args)
    {

        // Initializing the map
        ConcurrentSkipListMap<Integer, Integer>
            mpp = new ConcurrentSkipListMap<Integer,
                                            Integer>();

        // Adding elements to this map
        for (int i = 1; i <= 5; i++)
            mpp.put(i, i);

        // Checks if 4 is present in the map
        if (mpp.containsKey(4))
            System.out.println("4 is present"
                               + " in the mpp.");
        else
            System.out.println("4 is not present"
                               + " in the mpp.");
    }
}

Reference: https://docs.oracle.com/javase/9/docs/api/java/util/concurrent/ConcurrentSkipListMap.html#containsKey-java.lang.Object-