Certainly! Here are the top 5 ASP interview questions along with detailed answers:
1. What is ASP and how does it work?
Answer:
ASP (Active Server Pages) is a server-side scripting technology developed by Microsoft that allows web developers to create dynamic and interactive web pages. It works by embedding script code (typically written in VBScript or JScript) within HTML pages. When a client requests an ASP page, the web server processes the script code, generates HTML dynamically, and sends the final HTML to the client’s browser. The key components include:
- HTML Markup: Defines the structure of the page.
- ASP Script: Contains server-side code for logic processing.
- Server-Side Objects: Such as `Request`, `Response`, `Session`, and `Application` for handling web requests and responses.
2. What are the main differences between Classic ASP and ASP.NET?
Answer:
- Language Support: Classic ASP uses VBScript or JScript, whereas ASP.NET supports multiple languages, including C#, VB.NET, and JScript.NET.
- Execution Model: Classic ASP is interpreted and executed on each request, while ASP.NET uses a compiled execution model, enhancing performance and security.
- Features: ASP.NET offers features like Web Forms, MVC architecture, data binding, server controls, and state management, which are not present in Classic ASP.
- Development Environment: ASP.NET development is typically done using Visual Studio, which provides advanced debugging, IntelliSense, and other productivity tools.
3. How does ASP handle state management?
Answer:
ASP manages state using several techniques:
- Session State: Stores user-specific data for the duration of a session using the `Session` object. Data is maintained on the server.
- Application State: Stores global data accessible to all users using the `Application` object. Useful for global variables and settings.
- Cookies: Small pieces of data stored on the client’s browser. Accessible through the `Request.Cookies` and `Response.Cookies` collections.
- Query Strings: Data passed in the URL. Accessible via the `Request.QueryString` collection.
- Hidden Fields: Store data on the client side within form fields. Accessible via the `Request.Form` collection.
4. How do you handle errors in ASP?
Answer:
Errors in ASP can be managed using the following techniques:
- On Error Resume Next: Skips to the next line in the code if an error occurs.
- Error Object: Use the `Err` object to capture and handle errors. Key properties include `Err.Number`, `Err.Description`, and `Err.Source`.
- Custom Error Pages: Configure error handling to redirect to a custom error page using the `ErrorPage` attribute in the `<%@ Page %>` directive.
- Using `Try...Catch` Blocks: In ASP.NET, use `Try...Catch` blocks to catch and handle exceptions, providing a structured way to handle errors.
5. What is the purpose of the `Global.asa` file in ASP?
Answer:
The `Global.asa` file, also known as the application file, is used to define application-level and session-level events in ASP. It allows developers to write code that runs at specific points in the application lifecycle, such as:
- Application_OnStart: Runs when the application starts.
- Application_OnEnd: Runs when the application ends.
- Session_OnStart: Runs when a new session is started.
- Session_OnEnd: Runs when a session ends.
These events are useful for initializing application settings, managing user sessions, and performing cleanup tasks. The `Global.asa` file is placed in the root directory of the website.
These questions and answers should give you a solid foundation for your ASP interview preparation!