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Java Collections - PriorityQueue.offer() Examples

Java Collections Java Java API

Class:

java.util.PriorityQueue

Method:

public boolean offer(E e)

Inserts the specified element into this priority queue. As PriorityQueue is not a capacity-restricted queue, this method always returns true.

Examples

package com.logicbig.example.priorityqueue;

import java.util.PriorityQueue;

public class OfferExample {

    public static void main(String... args) {
        PriorityQueue<String> pq = new PriorityQueue<>();
        boolean b = pq.offer("one");
        System.out.println(b);
        b = pq.offer("two");
        System.out.println(b);
        System.out.println(pq);
    }
}

Output

true
true
[one, two]

PriorityQueue does not allow null elements:

package com.logicbig.example.priorityqueue;

import java.util.PriorityQueue;

public class OfferExample2 {

    public static void main(String... args) {
        PriorityQueue<String> pq = new PriorityQueue<>();
        pq.offer(null);
    }
}

Output

Caused by: java.lang.NullPointerException
	at java.base/java.util.PriorityQueue.offer(PriorityQueue.java:337)
	at com.logicbig.example.priorityqueue.OfferExample2.main(OfferExample2.java:15)
	... 6 more

See Also