ReactJS Practice Test

State is the place where a React component stores data it can change over time. When you update that data, React re-renders the component so the UI stays in sync with the current values. This is why the statement in the question matches how React components manage their own dynamic information: the component uses state to hold data it can alter, such as user input, toggles, counters, or form fields. Props, on the other hand, come from outside the component and are read-only inside it. They’re useful for configuring a component, but the component itself shouldn’t try to mutate them. If you need to reflect changes from outside, you’d typically lift state up or have the parent pass a new prop value, not mutate the prop directly. The idea that state should be mutated by external components is also not how React state works—the component owns its own state, and updates to it should go through the provided update mechanism (like setState or a setter from useState). Similarly, props are not meant to manage internal changes; they’re the inputs the component receives from its parent. In short, state is the right tool for internal, changeable data, which is why the statement is correct.