Question

__________ is used to insert a new element to the queue at the __________ end.

• A. DEQUEUE ; front
• B. ENQUEUE ; front
• C. DEQUEUE ; rear
• D. ENQUEUE ; rear

Hint:

Remember this layout:
- Insertion $\rightarrow$ ENQUEUE $\rightarrow$ REAR end.
- Deletion $\rightarrow$ DEQUEUE $\rightarrow$ FRONT end.
This is standard across all computer science exams!

Answer 1

The Correct Option is D

Step 1: Understanding the Question:
The question asks to identify the correct terms for inserting a new element into a queue and the specific end of the queue where insertions are performed.

Step 2: Key Operational Rules of a Queue:
- A Queue is a linear data structure working under the First-In, First-Out (FIFO) principle.
- It has two distinct ends:
- Front End: The position where elements are deleted (removed). This operation is called DEQUEUE.
- Rear End: The position where elements are inserted (added). This operation is called ENQUEUE.

Step 3: Detailed Explanation:
- Let us evaluate the options:
- Option (A) is incorrect because DEQUEUE is a removal operation, and it happens at the front, not insertion.
- Option (B) is incorrect because ENQUEUE (insertion) does not occur at the front.
- Option (C) is incorrect because DEQUEUE does not occur at the rear, and it is a deletion operation.
- Option (D) correctly states that ENQUEUE is the operation used to insert a new element and that it takes place at the rear end of the queue.

Step 4: Final Answer:
ENQUEUE is used to insert a new element to the queue at the rear end.
Hence, option (D) is the correct choice.