Trois Infotech Interview Questions and Answers

Two way binding in Angular allows automatic synchronization of data between the model and the view.

• Two way binding is achieved using the ngModel directive.

• Changes made in the view are automatically reflected in the model and vice versa.

• It simplifies the code and reduces the need for manual event handling.

• Example:

Express is a web application framework for Node.js. RESTful API is an architectural style for building web services.

• Express is a popular framework for building web applications using Node.js

• It provides a set of features for handling HTTP requests and responses

• RESTful API is an architectural style for building web services that use HTTP methods to perform CRUD operations

• It uses standard HTTP methods like GET, POST, PUT,...read more

Node is asynchronous, meaning it can handle multiple requests at once without blocking the main thread.

• Node uses an event-driven, non-blocking I/O model

• Callbacks are used to handle asynchronous operations

• Example: Reading a file using fs module

• Example: Making an HTTP request using http module

Synchronous data in Node.js can be handled using callbacks or promises.

• Use callbacks to handle synchronous data in Node.js

• Promises can also be used to handle synchronous data

• Avoid using synchronous code in Node.js as it can block the event loop

CRUD stands for Create, Read, Update, and Delete. It refers to the basic operations performed on a database.

• Create - inserting new data into the database

• Read - retrieving data from the database

• Update - modifying existing data in the database

• Delete - removing data from the database

• CRUD operations are essential for managing data in a database

• Examples include adding a new user, updating a product's price, or deleting a cu...read more

MongoDB is better suited for handling unstructured data and offers better scalability and performance compared to MySQL.

• MongoDB is a NoSQL database that allows for flexible and dynamic schema design.

• MongoDB is better suited for handling large amounts of unstructured data, such as social media posts or sensor data.

• MongoDB offers better scalability and performance compared to MySQL, especially for write-heavy application...read more

Observables are a way to handle asynchronous data streams in Angular.

• Observables are similar to Promises but can emit multiple values over time.

• They can be created using the RxJS library.

• They are often used for handling HTTP requests and real-time data updates.

• Operators can be used to transform, filter, and combine observables.

• Subscriptions are used to listen to the emitted values and handle errors and completion.

A callback is a function passed as an argument to another function, which is then invoked inside the outer function.

• Callbacks are used to execute code asynchronously, such as when an event occurs or when data is retrieved from a server.

• They are commonly used in JavaScript for event handling, AJAX requests, and timers.

• Callbacks can also be used for error handling, allowing the caller to handle errors that occur inside t...read more