Java ConcurrentSkipListSet contains()方法

java.util.concurrent.ConcurrentSkipListSet的 contains( )方法是Java中的一个内置函数，如果指定的元素存在于这个集合中，则返回一个真布尔值，否则返回假。

语法

ConcurrentSkipListSet.contains(Object o)

参数： 该函数接受一个单一的参数o，即被检查是否存在于这个集合中。

返回值： 该函数返回一个布尔值。如果指定的元素存在于这个集合中，它就返回True，否则就返回False。

下面的程序说明了ConcurrentSkipListSet.contains()方法。

程序1 :

// Java Program Demonstrate contains()
// method of ConcurrentSkipListSet
  
import java.util.concurrent.*;
  
class ConcurrentSkipListSetContainsExample1 {
    public static void main(String[] args)
    {
  
        // Initializing the set
        ConcurrentSkipListSet<Integer>
            set = new ConcurrentSkipListSet<Integer>();
  
        // Adding elements to this set
        for (int i = 10; i <= 15; i++)
            set.add(i);
  
        // Checks if 9 is present in the set
        if (set.contains(9))
            System.out.println("9 is present in the set.");
        else
            System.out.println("9 is not present in the set.");
    }
}

输出。

9 is not present in the set.

程序2

// Java Program Demonstrate contains()
// method of ConcurrentSkipListSet */
  
import java.util.concurrent.*;
  
class ConcurrentSkipListSetContainsExample2 {
    public static void main(String[] args)
    {
  
        // Initializing the set
        ConcurrentSkipListSet<String>
            set = new ConcurrentSkipListSet<String>();
  
        // Adding elements to this set
        set.add("Gfg");
        set.add("is");
        set.add("fun");
  
        // Checks if Gfg is present in the set
        if (set.contains("Gfg"))
            System.out.println("Gfg is present in the set.");
        else
            System.out.println("Gfg is not present in the set.");
    }
}

输出。