VOOZH about

URL: https://www.geeksforgeeks.org/java/priorityqueue-toarray-method-in-java/

⇱ PriorityQueue toArray() Method in Java - GeeksforGeeks

  • Courses
  • Tutorials
  • Interview Prep

PriorityQueue toArray() Method in Java

Last Updated : 10 Dec, 2018
  1. The java.util.PriorityQueue.toArray() method in Java is used to form an array of the same elements as that of the Priority Queue. Basically, it copies all the element from a priority queue to a new array. Syntax: 
    Object[] arr = Priority_Queue.toArray()
    Parameters: The method does not take any parameters. Return Value: The method returns an array containing the elements similar to the priority queue. Below programs illustrate the java.util.PriorityQueue.toArray() method. Program 1:
    Output: 
    The PriorityQueue: [For, Geeks, To, Welcome, Geeks]
The array is:
For
Geeks
To
Welcome
Geeks
    Program 2:
    Output: 
    The PriorityQueue: [5, 10, 25, 20, 15, 30]
The array is:
5
10
25
20
15
30
  2. The java.util.PriorityQueue.toArray(arr[]) method in Java is used to form an array of the same elements as that of the Priority Queue. Basically, it copies all the element from a priority queue to a new array. It creates multiple arrays, unlike the previous method without parameters. This method copies all of the elements into the arr[]. Syntax: 
    Object[] arr1 = Priority_Queue.toArray(arr[])
    Parameters: The method accepts one parameter arr[] into which all of the elements of the queue are to be copied. Return Value: The method returns an array containing the elements similar to the priority queue.
      Exception: The method might throw two types of exception:
    • ArrayStoreException: When the mentioned array is of the different type and is not able to compare with the elements mentioned in the queue.
    • NullPointerException: If the array is Null, then this exception is thrown.
    Below program illustrates the working of the java.util.PriorityQueue.toArray(arr[]) method.
Output: 
The PriorityQueue: [For, Geeks, To, Welcome, Geeks]
The arr[] is:
For
Geeks
To
Welcome
Geeks

The arr1[] is:
For
Geeks
To
Welcome
Geeks
Comment