ArrayBlockingQueue toString() Method in Java

The toString() method of ArrayBlockingQueue class is used to get a string representation of the objects of ArrayBlockingQueue. The string of ArrayBlockingQueue contains elements of ArrayBlockingQueue in the order from first(head) to last(tail), enclosed in square brackets(“[]”). The elements are separated by the characters”, ” (comma and a space). So basically the toString() method is used to convert all the elements of ArrayBlockingQueue into a String.

Syntax:

public String toString()

Return Value: The method returns an String representation of ArrayBlockingQueue.

Below programs illustrates toString() method of ArrayBlockingQueue class:

Program 1:

// Program to demonstrate how to apply toString() method
// of ArrayBlockingQueue Class.

import java.util.concurrent.ArrayBlockingQueue;


public class GFG {

public static void main(String[] args) {
    // Define capacity of ArrayBlockingQueue
    int capacity = 5;

    // Create object of ArrayBlockingQueue
    ArrayBlockingQueue<Integer> queue =
        new ArrayBlockingQueue<Integer>(capacity);

    // Add 5 elements to ArrayBlockingQueue
    queue.offer(423);
    queue.offer(422);
    queue.offer(421);
    queue.offer(420);
    queue.offer(424);

    // Print queue
    System.out.println("Queue is "+queue);

    // Call toString() method and Create an iterator
    String stringRepresentation=queue.toString();

    // Print String value returned by toString() method
    System.out.println("\nThe String returned by toString():");
    System.out.println(stringRepresentation);


    }
}

Output:

Queue is [423, 422, 421, 420, 424]

The String returned by toString():
[423, 422, 421, 420, 424]

Program 2:

// Program Demonstrate how to apply toString() method
// of ArrayBlockingQueue Class.

import java.util.concurrent.ArrayBlockingQueue;


public class GFG {

public static void main(String[] args) {
    // Define capacity of ArrayBlockingQueue
    int capacity = 10;

    // Create object of ArrayBlockingQueue
    ArrayBlockingQueue<String> queue =
                    new ArrayBlockingQueue<String>(capacity);

    // Add 5 elements to ArrayBlockingQueue
    queue.offer("User");
    queue.offer("Employee");
    queue.offer("Manager");
    queue.offer("Analyst");
    queue.offer("HR");
    queue.offer("Tester");

    // Print queue
    System.out.println("Queue is "+queue);

    // Call toString() method and Create an iterator
    String stringRepresentation=queue.toString();

    // Print String value returned by toString() method
    System.out.println("\nThe String returned by toString():");
    System.out.println(stringRepresentation);


    }
}

Output:

Queue is [User, Employee, Manager, Analyst, HR, Tester]

The String returned by toString():
[User, Employee, Manager, Analyst, HR, Tester]

Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ArrayBlockingQueue.html#toString