ASP.NET Core Web API Interview Question #14

What are HTTP status codes, and why are they important in Web APIs?

Web API & REST Fundamentals, Controllers, HTTP Methods & Status Codes Junior Beginner

Quick Interview Answer

HTTP status codes communicate the high-level outcome of a request using a standardized protocol contract. Clients can use the status code before interpreting the response body.

Detailed Explanation

HTTP status codes communicate the high-level outcome of a request using a standardized protocol contract. Clients can use the status code before interpreting the response body.

A well-designed API uses status codes consistently so success, validation problems, authentication failures, missing resources, conflicts, and server failures are distinguishable without relying on custom text alone.

Code Example

return Ok(product);              // 200
return CreatedAtAction(...);       // 201
return NoContent();                // 204
return BadRequest();               // 400
return NotFound();                 // 404