G2 Technology Solutions Interview Questions and Answers

Closures are functions that retain access to their lexical scope, even when executed outside that scope.

• A closure is created when a function is defined inside another function.

• Closures can access variables from their parent function's scope.

• Example: function outer() { let x = 10; return function inner() { return x; }; }

• Closures are often used for data encapsulation and creating private variables.

• They are also usef...read more

The spread operator expands iterable elements into individual elements, simplifying array and object manipulation in JavaScript.

• Syntax: The spread operator is represented by three dots (...).

• Example with arrays: const arr1 = [1, 2]; const arr2 = [...arr1, 3]; // arr2 is [1, 2, 3]

• Example with objects: const obj1 = { a: 1 }; const obj2 = { ...obj1, b: 2 }; // obj2 is { a: 1, b: 2 }

• Useful for merging arrays or object...read more

Deadlocking in SQL occurs when two or more transactions are waiting for each other to release locks, causing them to be stuck indefinitely.

• Deadlocking happens when two transactions each have a lock on a resource that the other transaction needs.

• It can lead to a situation where neither transaction can proceed, causing a deadlock.

• Deadlocks can be resolved by setting appropriate isolation levels, using timeouts, or r...read more

Facts are measurable data points while dimensions provide context to the facts in a data model.

• Facts are quantitative data that can be measured or counted.

• Dimensions provide context to the facts and are descriptive attributes that help categorize or filter the data.

• For example, in a sales data model, the fact could be total revenue while dimensions could include product category, region, and time period.

Design a system for handling user authentication and authorization in a web application.

• Use OAuth for authentication to allow users to log in using their existing accounts from providers like Google, Facebook, etc.

• Implement role-based access control (RBAC) for authorization to define different levels of access for different users.

• Store user credentials securely using hashing algorithms like bcrypt.

• Use JSON Web Tok...read more

Associations/relations in Rails refer to the way different models are connected to each other.

• Rails associations are used to define relationships between different models in a Rails application.

• There are different types of associations in Rails such as belongs_to, has_one, has_many, and has_and_belongs_to_many.

• Associations are defined using ActiveRecord macros in the model files.

• For example, a User model may have ...read more