Electron.js Interview Questions and Answers
Freshers / Beginner level questions & answers
Ques 1. What is Electron.js?
Electron.js is an open-source framework developed by GitHub for building cross-platform desktop applications with web technologies like HTML, CSS, and JavaScript.
Ques 2. How can you disable the Electron security warnings?
Electron displays security warnings in the developer console. These warnings can be disabled by setting the 'ELECTRON_DISABLE_SECURITY_WARNINGS' environment variable or using the 'app.commandLine.appendSwitch' method in the main process.
Intermediate / 1 to 5 years experienced level questions & answers
Ques 3. Explain the main process and renderer process in Electron.
The main process manages the lifecycle of the application and creates web pages using renderer processes. Renderer processes are responsible for rendering the UI and run in separate instances for each opened window.
Ques 4. How can you communicate between the main process and renderer process in Electron?
Inter-process communication (IPC) is used to communicate between the main process and renderer processes. Electron provides modules like 'ipcMain' and 'ipcRenderer' for sending and receiving messages.
Ques 5. Explain Electron's 'Main' and 'Renderer' threads.
The 'Main' thread manages the Electron application and runs the main script. The 'Renderer' thread runs the web page content and is responsible for rendering the UI. Each Electron window has its own 'Renderer' thread.
Ques 6. Explain the Electron app life cycle events.
Electron apps have several life cycle events, including 'ready', 'window-all-closed', 'before-quit', 'will-quit', and 'quit'. These events help manage the initialization, window creation, and quitting processes.
Ques 7. How can you package an Electron application?
Electron applications can be packaged using tools like 'electron-builder' or 'electron-packager'. These tools allow you to package the app for different platforms and architectures.
Ques 8. What is Electron's 'remote' module used for?
The 'remote' module enables communication and interaction between the main process and renderer processes by allowing objects to be used across processes. It provides a way to access objects from the main process in the renderer process.
Ques 9. What is the purpose of the 'BrowserWindow' module in Electron?
'BrowserWindow' is used to create and control browser windows in Electron. It allows you to customize window properties, handle events, and control window behavior.
Ques 10. Explain the concept of 'Electron Prebuilt' and 'Electron' packages.
'Electron Prebuilt' and 'Electron' packages are npm packages that provide Electron binaries. 'Electron Prebuilt' is an older version, while 'Electron' provides the latest stable release. Developers can use these packages to run Electron apps without having to manually install Electron globally.
Ques 11. How can you handle menu creation in Electron?
Menus in Electron can be created using the 'Menu' module. You can define menu items, submenus, and their functionality. Menus can be attached to specific windows or the application as a whole.
Ques 12. How can you handle file dialogs in Electron?
Electron provides the 'dialog' module for handling file dialogs. Developers can use methods like 'showOpenDialog' and 'showSaveDialog' to display file selection and save dialogs, respectively.
Ques 13. How does Electron support multi-window applications?
Electron enables the creation of multiple windows in an application. Each window runs in its own renderer process, providing isolation. Developers can manage these windows using the 'BrowserWindow' module.
Ques 14. What is the purpose of 'app.on('will-quit', callback)' in Electron?
The 'will-quit' event is emitted before the application is about to quit. Developers can use this event to perform cleanup tasks or prevent the application from quitting by calling 'event.preventDefault()'.
Ques 15. Explain the 'webPreferences' option in the 'BrowserWindow' module.
The 'webPreferences' option allows developers to configure various preferences for the web page content, including enabling Node.js integration, setting the preload script, and controlling context isolation.
Ques 16. What is the purpose of the 'globalShortcut' module in Electron?
The 'globalShortcut' module is used to register and unregister global keyboard shortcuts in Electron. It allows developers to define custom key combinations that trigger specific actions in the application.
Ques 17. How can you access command-line arguments in an Electron app?
Command-line arguments can be accessed using the 'process.argv' array in the main process. The 'remote' module can be used in the renderer process to access command-line arguments from the main process.
Experienced / Expert level questions & answers
Ques 18. What is the purpose of the 'preload' script in Electron?
The 'preload' script is a JavaScript file specified in the Electron BrowserWindow options. It runs in the renderer process and has access to Node.js APIs before the DOM content is loaded. It allows customization of the environment for the renderer process.
Ques 19. Explain the role of 'webContents' in Electron.
'webContents' is an Electron module that represents the web page content in a window. It allows you to control and manipulate the content, handle events, and execute scripts in the renderer process.
Ques 20. What is Electron's 'autoUpdater' module used for?
The 'autoUpdater' module is used to enable automatic updates for Electron applications. It allows apps to check for updates and download new versions from a server.
Ques 21. Explain how Electron handles security and sandboxing.
Electron uses the Chromium browser, which employs a multi-process architecture with a main process and renderer processes. Each renderer process is sandboxed to enhance security, preventing direct access to Node.js modules and system resources.
Ques 22. What is the 'contextIsolation' option in Electron and why is it used?
The 'contextIsolation' option, when set to true, isolates the renderer processes by running JavaScript code in a separate context. This enhances security by preventing the renderer processes from directly accessing the 'require' function and other Node.js modules.
Ques 23. Explain the role of the 'BrowserView' module in Electron.
'BrowserView' is used to embed web content within a window in Electron. It allows developers to create separate views within a single window, each with its own 'webContents' and lifecycle.
Ques 24. Explain the purpose of the 'session' module in Electron.
The 'session' module allows developers to customize the behavior of the Electron session, such as configuring HTTP headers, handling cookies, and managing browser sessions. It provides methods to intercept requests and responses.
Most helpful rated by users:
- How can you package an Electron application?
- Explain Electron's 'Main' and 'Renderer' threads.
- How does Electron support multi-window applications?
- Explain the Electron app life cycle events.
- What is the purpose of the 'BrowserWindow' module in Electron?