Java LinkedList offer(E) Method

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Description

The Java LinkedList offer(E e) method inserts the specified element E at the end of this linkedList. It is similar to add() method.

Declaration

Following is the declaration for java.util.LinkedList.offer() method

public boolean offer(E e)

Parameters

e − The element to be added at the end.

Return Value

This method returns true if the element was added to this linkedList, else false.

Exception

NullPointerException − if the specified element is null.

Inserting an Element to the End of the LinkedList of Integers Example

The following example shows the usage of Java LinkedList offer(E) method with Integers. We're adding few elements to list using add() method and then using offer() method, we're adding two elements in the end. Lastly we're printing the LinkedList object to see the final result.

package com.tutorialspoint;

import java.util.LinkedList;

public class LinkedListDemo {
   public static void main(String[] args) {

      // create an empty linkedList
      LinkedList<Integer> linkedList = new LinkedList<>();

      // use add() method to add elements in the linkedList
      linkedList.add(1);
      linkedList.add(2);
      linkedList.add(3);
      linkedList.add(4);        
      linkedList.add(5);
      linkedList.add(6);

      // the values will be printed in the same order
      linkedList.offer(7);
      linkedList.offer(8);

      // let us print all the elements available in linkedList
      System.out.println("LinkedList = " + linkedList);      
   }
}

Output

Let us compile and run the above program, this will produce the following result −

LinkedList = [1, 2, 3, 4, 5, 6, 7, 8]

Inserting an Element to the End of the LinkedList of Strings Example

The following example shows the usage of Java LinkedList offer(E) method with Strings. We're adding few elements to list using add() method and then using offer() method, we're adding two elements in the end. Lastly we're printing the LinkedList object to see the final result.

package com.tutorialspoint;

import java.util.LinkedList;

public class LinkedListDemo {
   public static void main(String[] args) {

      // create an empty linkedList
      LinkedList<String> linkedList = new LinkedList<>();

      // use add() method to add elements in the linkedList
      linkedList.add("A");
      linkedList.add("B");
      linkedList.add("C");
      linkedList.add("D");        
      linkedList.add("E");
      linkedList.add("F");

      // the values will be printed in the same order
      linkedList.offer("G");
      linkedList.offer("H");

      // let us print all the elements available in linkedList
      System.out.println("LinkedList = " + linkedList);      
   }
}

Output

Let us compile and run the above program, this will produce the following result −

LinkedList = [A, B, C, D, E, F, G, H]

Inserting an Element to the End of the LinkedList of Objects Example

The following example shows the usage of Java LinkedList offer(E) method with Student objects. We're adding few elements to list using add() method and then using offer() method, we're adding two elements in the end. Lastly we're printing the LinkedList object to see the final result.

package com.tutorialspoint;

import java.util.LinkedList;

public class LinkedListDemo {
   public static void main(String[] args) {

      // create an empty linkedList
      LinkedList<Student> linkedList = new LinkedList<>();

      // use add() method to add elements in the linkedList
      linkedList.add(new Student(1, "Julie"));
      linkedList.add(new Student(2, "Robert"));
      linkedList.add(new Student(3, "Adam"));

      // use offer() method to add element at the end of the linkedList
      linkedList.offer(new Student(4, "Rohan"));
      linkedList.offer(new Student(5, "Sohan"));

      // let us print all the elements available in linkedList
      System.out.println("LinkedList = " + linkedList);      
   }
}

class Student {
   int rollNo;
   String name;

   Student(int rollNo, String name){
      this.rollNo = rollNo;
      this.name = name;
   }

   @Override
   public String toString() {
      return "[ " + this.rollNo + ", " + this.name + " ]";
   }
}

Output

Let us compile and run the above program, this will produce the following result −

LinkedList = [[ 1, Julie ], [ 2, Robert ], [ 3, Adam ], [ 4, Rohan ], [ 5, Sohan ]]