ReactJS by itself doesn’t handle themes. It’s a library for building user interfaces, mostly for single-page applications.
However, you can definitely implement themes in your React application using various techniques. There are several ways to implement themes:
1. CSS-in-JS libraries: Libraries like styled-components or emotion leverage JavaScript to write CSS. They have built-in theming capabilities using React’s Context API.
1. CSS Variables: One of the simplest ways to handle theming is through CSS custom properties or variables.
1. Stylesheet swapping: You can have different stylesheets for each of your themes and swap them in runtime based on the selected theme.
1. Context API: Using the context API, a theme can be switched globally by changing state and that change would propagate across the whole app triggering a re-render with the new theme.
1. Third-party Libraries: Libraries like Material UI provides in-built theming solutions where you can customize your color palette, typography, etc.
Remember that React itself doesn’t have a notion of themes, you’ll have to manage it on your own or use external libraries/packages. The actual implementation will largely depend on the project requirements and the specific needs of the project.
