Java PriorityBlockingQueue contains()用法及代碼示例

contains(Object o)方法檢查PriorityBlockingQueue是否包含對象o。當且僅當此隊列包含至少一個等於作為參數傳遞的對象o的元素e，即equals(o)時，此方法返回true。如果queue不包含Object o，則方法返回false。

用法:

public boolean contains(Object o)

參數：此方法采用強製性參數o，該參數是要在PriorityBlockingQueue中檢查的對象。

返回值：如果此隊列包含作為參數傳遞的對象，則此方法返回true。否則返回false。

異常：此方法不會引發任何異常。

下麵的程序說明PriorityBlockingQueue的contains()方法：

示例1:

// Java Program Demonstrate contains(Object o) 
// method of PriorityBlockingQueue 
  
import java.util.concurrent.PriorityBlockingQueue; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
        // define capacity of PriorityBlockingQueue 
        int capacityOfQueue = 5; 
  
        // create object of PriorityBlockingQueue 
        PriorityBlockingQueue<Integer> PrioQueue 
            = new PriorityBlockingQueue<Integer>(capacityOfQueue); 
  
        // Add element to PriorityBlockingQueue 
        PrioQueue.add(4641515); 
        PrioQueue.add(46514561); 
        PrioQueue.add(56156); 
        PrioQueue.add(948964165); 
  
        // print PrioQueue 
        System.out.println("PrioQueue: " + PrioQueue); 
  
        // check whether PriorityBlockingQueue contains 56156 
        boolean answer1 = PrioQueue.contains(56156); 
  
        // print result 
        System.out.println("PriorityBlockingQueue contains "
                           + "number 56156 : "
                           + answer1); 
  
        // check whether PriorityBlockingQueue contains 46545 
        boolean answer2 = PrioQueue.contains(46545); 
  
        // print result 
        System.out.println("PriorityBlockingQueue contains"
                           + " number 46545 : "
                           + answer2); 
    } 
}

輸出：

PrioQueue: [56156, 46514561, 4641515, 948964165]
PriorityBlockingQueue contains number 56156 : true
PriorityBlockingQueue contains number 46545 : false

示例2:演示PriorityBlockingQueue的contains()方法，其中包含名稱列表。

// Java Program Demonstrate contains(Object o) 
// method of PriorityBlockingQueue 
  
import java.util.concurrent.PriorityBlockingQueue; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
        // define capacity of PriorityBlockingQueue 
        int capacityOfQueue = 10; 
  
        // create object of PriorityBlockingQueue 
        PriorityBlockingQueue<String> names 
            = new PriorityBlockingQueue<String>(capacityOfQueue); 
  
        // Add names 
        names.add("Geeks"); 
        names.add("forGeeks"); 
        names.add("A"); 
        names.add("Computer"); 
        names.add("Portal"); 
  
        // print queue details 
        System.out.println("List of Names: " + names); 
  
        // check whether PriorityBlockingQueue contains Geeks 
        boolean answer1 = names.contains("Geeks"); 
  
        // print result 
        System.out.println("Does names contains "
                           + "Geeks: "
                           + answer1); 
  
        // check whether PriorityBlockingQueue contains SandeepJain 
        boolean answer2 = names.contains("SandeepJain"); 
  
        // print result 
        System.out.println("Does names contains "
                           + "SandeepJain: "
                           + answer2); 
    } 
}

輸出：

List of Names: [A, Computer, Geeks, forGeeks, Portal]
Does names contains Geeks: true
Does names contains SandeepJain: false

參考：
https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/PriorityBlockingQueue.html#contains-java.lang.Object-

相關用法

注：本文由純淨天空篩選整理自AmanSingh2210大神的英文原創作品 PriorityBlockingQueue contains() method in Java。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。