What operation removes an item from the front of a queue?

What operation removes an item from the front of a queue?

• A. Enqueue
• B. Dequeue
• C. Insert
• D. Remove

Answer: (B)

In a queue, items are processed in the order they arrive—first in, first out. The item at the front is the oldest waiting, and the operation that removes that front item is called dequeue. It takes the front element out and then moves the front pointer to the next item, effectively shrinking the queue. Enqueue adds a new item to the back, not removal. Insert isn’t a standard queue operation, and Remove is too generic and doesn’t specify removing from the front. So removing from the front is accomplished by dequeue.

In a queue, items are processed in the order they arrive—first in, first out. The item at the front is the oldest waiting, and the operation that removes that front item is called dequeue. It takes the front element out and then moves the front pointer to the next item, effectively shrinking the queue. Enqueue adds a new item to the back, not removal. Insert isn’t a standard queue operation, and Remove is too generic and doesn’t specify removing from the front. So removing from the front is accomplished by dequeue.