Priority Queue Java Add Method throws syntax error and misplaced construct error

Question

I wanted to learn how to use Priority Queues in Java for solving Algorithim based problems, I cant seem to get my priority queue to get the add method.

import java.util.PriorityQueue;

public class PQueue {

PriorityQueue pq = new PriorityQueue();
// or
PriorityQueue<Integer> pq = new PriorityQueue<Integer>();

pq.add(2);
// Java fails to recognise the add method. Moreover, on pressing spacebar + enter after pq. 

// i do not get anny suggestion for any methods supported by priority queue. 
// Is this because I am not specifying a comparator, 
// isnt integer suppose to have natural ordering by default. Need help. Feeling like a moron.


}

Answer 1

You have to write that code inside a method follow the code below

package temp;
import java.util.PriorityQueue;

public class PQueue {




    public static void main(String[] args) {

        PriorityQueue<Integer> pq = new PriorityQueue<Integer>();
        pq.add(2);



    }

}

The problem with your solution is whatever you have written is directly inside the class and so you are getting members. A class should ideally have data members and methods.

This might help you in understanding the logic

Class Person{

private String name;
private int age;
private String address;

public String getName() {
    return name;
}


public void setName(String name) {
    this.name = name;
}



public int getAge() {
    return age;

}

public void setAge(int age) {
    this.age = age;
}



public String getAddress() {
    return address;
}



public void setAddress(String address) {
    this.address = address;
}

}

All data manipulation should be done inside a method as shown in getters and settors in the above code.

The other place to put the same code is inside a static block as shown below

static {

        PriorityQueue<Integer> pq = new PriorityQueue<Integer>();
        pq.add(2);
    }