Which statement best describes props and state?

Which statement best describes props and state?

• A. Props are inputs from a parent and read-only in the child; state is internal and can change over time.
• B. Props are internal state; state is provided by the parent.
• C. Props are always mutable, state is never mutable.
• D. Props and state are the same thing.

Answer: (A)

Props are the inputs a parent passes to a child component. They come from above and, from the child’s perspective, are read-only—the child should not mutate them. This keeps the data flow predictable: the parent controls the values by rendering the child with new props as needed. State, in contrast, lives inside the component itself. It represents data the component owns and can update over time in response to events, user actions, or data changes. When state changes, the component re-renders to reflect the new UI. So, the statement is the best description because it captures the two distinct roles: props as external, immutable inputs from a parent, and internal, mutable state that a component manages itself. It also aligns with the typical pattern where a child may notify the parent via callbacks to effect changes, rather than mutating props directly.

Props are the inputs a parent passes to a child component. They come from above and, from the child’s perspective, are read-only—the child should not mutate them. This keeps the data flow predictable: the parent controls the values by rendering the child with new props as needed.

State, in contrast, lives inside the component itself. It represents data the component owns and can update over time in response to events, user actions, or data changes. When state changes, the component re-renders to reflect the new UI.

So, the statement is the best description because it captures the two distinct roles: props as external, immutable inputs from a parent, and internal, mutable state that a component manages itself. It also aligns with the typical pattern where a child may notify the parent via callbacks to effect changes, rather than mutating props directly.