What is React.StrictMode and why is it used during development?

What is React.StrictMode and why is it used during development?

• A. StrictMode helps in production optimizations.
• B. StrictMode enables additional checks in development, such as double-invoking certain lifecycle methods, and does not affect production.
• C. StrictMode prevents rendering in development.
• D. StrictMode is required for all components.

Answer: (B)

React.StrictMode is a development-only wrapper that enables extra checks and warnings for its descendants. It doesn’t render any visible UI itself and has no impact on production builds. In development, it may double-invoke certain lifecycle methods and render paths, and it can invoke effects in ways that help you spot side effects and unsafe patterns early. This helps you identify issues like code that relies on side effects during render or uses deprecated lifecycles, before those problems make it into production. Since it's only active during development, production performance and behavior remain unaffected. It’s optional and not required for all components.

React.StrictMode is a development-only wrapper that enables extra checks and warnings for its descendants. It doesn’t render any visible UI itself and has no impact on production builds. In development, it may double-invoke certain lifecycle methods and render paths, and it can invoke effects in ways that help you spot side effects and unsafe patterns early. This helps you identify issues like code that relies on side effects during render or uses deprecated lifecycles, before those problems make it into production. Since it's only active during development, production performance and behavior remain unaffected. It’s optional and not required for all components.