TypeScript

TypeScript enhances JavaScript with static typing and improved developer tooling. On this page, you’ll learn about types, interfaces, enums, generics, utility types, type narrowing, and advanced TypeScript patterns. You’ll also find interview questions focused on building scalable and maintainable frontend applications using TypeScript.

Basics

Fundamental concepts of TypeScript and its core principles.

Type System

Understanding static typing, type inference, and type checking.

Variables & Declarations

Working with let, const, readonly, optional, and definite assignment.

Functions

Typing functions, parameters, return values, and overloads.

Arrays & Tuples

Using typed arrays, tuples, readonly arrays, and spread operators.

Union & Intersection Types

Combining multiple types using union and intersection patterns.

Enums

Working with numeric, string, and const enums.

Type Guards & Narrowing

Runtime checks and custom type guards for safe typing.

Advanced Types

Mapped, conditional, indexed access, and literal types.

Generics

Reusable and flexible code using generics.

Utility Types

Built-in utility types like Partial, Pick, Omit, Record.

Classes & OOP

Object-oriented programming with classes and inheritance.

Interfaces vs Types

Differences, similarities, and use cases.

Modules & Namespaces

Organizing code with ES modules and namespaces.

Asynchronous Programming

Promises, async/await, and async error handling.

Type Assertions & Casting

Type assertions, non-null assertions, and casting.

Null & Undefined Handling

Handling null, undefined, and optional chaining.

Configuration & Compiler Options

Understanding tsconfig.json and compiler behavior.

Decorators

Using experimental decorators in TypeScript.

TypeScript with Frameworks

Using TypeScript with React, Node.js, and backend frameworks.

Performance & Optimization

Improving compile-time and large project performance.

Best Practices

Recommended coding patterns and guidelines.

Testing & Tooling

Testing frameworks, linters, and dev tools.

Build & Deployment

Transpilation, bundling, and deployment strategies.

Advanced & Edge Cases

Declaration files, augmentation, and complex scenarios.