Java LinkedBlockingDeque contains()方法

LinkedBlockingDeque 的 contains(Object o) 方法检查参数中传递的元素是否存在于容器中。如果该元素存在于容器中，它将返回true，否则将返回false值。

语法

public boolean contains(Object o)

参数： 该方法接受一个强制性参数 o ，该参数在容器中的存在要在容器中检查。

返回： 如果该元素存在，该方法返回true，否则返回false。

下面的程序说明了LinkedBlockingDeque的contains()方法。

程序1 :

// Java Program Demonstrate contains()
// method of LinkedBlockingDeque
  
import java.util.concurrent.LinkedBlockingDeque;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws IllegalStateException
    {
  
        // create object of LinkedBlockingDeque
        LinkedBlockingDeque<Integer> LBD
            = new LinkedBlockingDeque<Integer>();
  
        // Add numbers to end of LinkedBlockingDeque
        LBD.add(10);
        LBD.add(20);
        LBD.add(30);
        LBD.add(40);
  
        // before removing print queue
        System.out.println("Linked Blocking Deque: " + LBD);
  
        // check for presence using function
        if (LBD.contains(10)) {
            System.out.println("Linked Blocking Deque contains 10");
        }
        else {
            System.out.println("Linked Blocking Deque does not contain 10");
        }
    }
}

输出:

Linked Blocking Deque: [10, 20, 30, 40]
Linked Blocking Deque contains 10

示例2

// Java Program Demonstrate contains()
// method of LinkedBlockingDeque
import java.util.concurrent.LinkedBlockingDeque;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws IllegalStateException
    {
  
        // create object of LinkedBlockingDeque
        LinkedBlockingDeque<String> LBD
            = new LinkedBlockingDeque<String>();
  
        // Add numbers to end of LinkedBlockingDeque
        LBD.add("ab");
        LBD.add("cd");
        LBD.add("fg");
        LBD.add("xz");
  
        // before removing print queue
        System.out.println("Linked Blocking Deque: " + LBD);
  
        // check for presence using function
        if (LBD.contains("go")) {
            System.out.println("Linked Blocking Deque contains 'go'");
        }
        else {
            System.out.println("Linked Blocking Deque does not contain 'go'");
        }
    }
}

输出:

Linked Blocking Deque: [ab, cd, fg, xz]
Linked Blocking Deque does not contain 'go'

参考资料: https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/LinkedBlockingDeque.html#contains(java.lang.Object)