Which operation adds an item to the top of a stack?

Which operation adds an item to the top of a stack?

• A. Push
• B. Pop
• C. Peek
• D. Enqueue

Answer: (A)

In a stack, you add and remove items from the top, following last-in, first-out behavior. The action that places a new item on the top of the stack is called pushing. When you push an element, it becomes the new top element, meaning it will be the next one removed when you perform a pop. Popping, by contrast, removes that top element. Peeking looks at the top element without removing it. Enqueue belongs to a different structure (a queue) and adds elements to the back, not the top of a stack. So the operation that adds an item to the top is push.

In a stack, you add and remove items from the top, following last-in, first-out behavior. The action that places a new item on the top of the stack is called pushing. When you push an element, it becomes the new top element, meaning it will be the next one removed when you perform a pop. Popping, by contrast, removes that top element. Peeking looks at the top element without removing it. Enqueue belongs to a different structure (a queue) and adds elements to the back, not the top of a stack. So the operation that adds an item to the top is push.