How can you catch synchronous errors occurring in a route handler in Express?
- Using try-catch blocks
- Using the catchError method
- Adding the error event listener
- Using the next() function
You can catch synchronous errors occurring in a route handler in Express by using try-catch blocks. This allows you to capture errors and handle them within your route handler function. The other options are not the typical way to catch synchronous errors in Express.
What is a Closure in JavaScript?
- A function with no parameters.
- A function that can be called only once.
- A function that has access to its own scope, as well as the outer (enclosing) function's scope.
- A function that returns a random value.
In JavaScript, a closure is a function that has access to its own scope, as well as the outer (enclosing) function's scope. This allows it to capture and remember values from the outer function even after the outer function has finished executing.
Which testing framework is commonly used for writing tests in Node.js applications?
- Mocha
- Jasmine
- Jest
- Chai
Jest is a popular testing framework commonly used for writing tests in Node.js applications. It provides a comprehensive toolset for testing and is known for its simplicity and speed.
The fs module provides both synchronous and asynchronous methods, identified by the ______ suffix for synchronous methods.
- async
- sync
- synchronous
- await
In the fs module of Node.js, synchronous methods are identified by the Sync suffix. For example, fs.readFileSync is a synchronous method for reading files, whereas asynchronous methods do not have this suffix.
When creating a custom lifecycle script, the ______ event can be used to perform tasks after the main event has completed.
- post
- after
- complete
- finish
When creating a custom lifecycle script in Node.js, you can use the post event to perform tasks after the main event has completed. This allows you to extend or customize the behavior of existing npm lifecycle events. The other options do not represent standard event names in npm scripts.
How can you set up ESLint to lint TypeScript files in a project?
- npm install --save-dev eslint @typescript-eslint/parser @typescript-eslint/eslint-plugin
- npm install --global eslint
- npm install --save-dev eslint
- npm install --save-dev eslint-plugin-typescript
To set up ESLint for TypeScript, you need to install eslint, @typescript-eslint/parser, and @typescript-eslint/eslint-plugin as dev dependencies. This combination allows ESLint to parse and analyze TypeScript code. The other options do not cover TypeScript-specific linting.
Which of the following is a commonly used configuration file for ESLint?
- .eslintrc.json
- .eslint-config
- .eslint-settings
- .lintfile
The commonly used configuration file for ESLint is .eslintrc.json. This file allows you to specify ESLint rules, plugins, and other configuration options for your project.
What type of files are generally served as static files in Express.js?
- HTML files
- Dynamic server scripts
- Configuration files
- Images, CSS, JavaScript
In Express.js, static files typically include images, CSS files, and JavaScript files. These files do not change dynamically and can be served directly to clients. HTML files are often dynamically generated, and configuration files are not typically served as static files.
You are developing a Node.js application where you need to perform a specific action immediately after the current operation completes. How would you use the process object to schedule this action?
- process.scheduleImmediate(() => { /* Action code */ });
- process.nextTick(() => { /* Action code */ });
- process.setImmediate(() => { /* Action code */ });
- process.waitForNext(() => { /* Action code */ });
To schedule a specific action immediately after the current operation completes, you should use process.setImmediate(() => { /* Action code */ });. This ensures that the action is placed in the event queue and executed as soon as possible after the current operation. The other options do not serve this purpose correctly.
How can you execute a block of code multiple times, as long as a specified condition is true, in JavaScript?
- for loop
- while loop
- if statement
- switch statement
In JavaScript, you can use a while loop to execute a block of code repeatedly as long as a specified condition is true. The for loop is used for iterating over a sequence, and if and switch statements are conditional constructs, not loops.
When creating a multidimensional array in JavaScript, each element of the main array is ______.
- an object
- a reference
- a function
- a prototype
When creating a multidimensional array in JavaScript, each element of the main array is a reference to another array or value. This allows for the creation of nested arrays. Changes made to the referenced arrays will affect the main array.
How can you make the properties of an object immutable in JavaScript?
- Using Object.freeze()
- Using Object.preventExtensions()
- Using Object.seal()
- Using Object.makeImmutable()
To make the properties of an object immutable in JavaScript, you can use the Object.freeze() method. This method prevents any changes to the object's properties, making them read-only. The other options, Object.preventExtensions() and Object.seal(), allow some level of modification but not full immutability, and Object.makeImmutable() is not a valid method in JavaScript.