Question

Which of the following is the top-level container in AWT?

• A. Panel
• B. Label
• C. Button
• D. Frame

Hint:

In AWT/Swing, there are two types of containers: top-level containers (like `Frame`, `JFrame`, `Dialog`) which create a window, and intermediate containers (like `Panel`, `JPanel`) which are used to group components inside other containers.

Answer 1

The Correct Option is D

In Java's AWT (Abstract Window Toolkit), components are placed inside containers. Containers can be nested within other containers.
A top-level container is a container that is not contained within any other container. It exists as a standalone window on the desktop.
Let's analyze the options:
(A) Panel: A `Panel` is a generic, simple container. It is used to group other components together. A `Panel` must be placed inside another container, so it is not a top-level container.
(B) Label: A `Label` is a component used to display text. It is not a container.
(C) Button: A `Button` is a component that triggers an action when clicked. It is not a container.
(D) Frame: A `Frame` is a top-level window with a title bar, a border, and buttons for minimizing, maximizing, and closing. Applets run in a frame provided by the browser, and standalone AWT applications are built using `Frame`. It is the primary top-level container. Other top-level containers are `Window` and `Dialog`.
Therefore, `Frame` is the top-level container among the choices.