Technical interview questions and answers are critical when preparing for an AJAX Interview because companies want to evaluate your understanding of asynchronous communication, XMLHttpRequest, JSON handling, DOM manipulation, and interactive web applications. AJAX is considered a core concept in modern web development, and many companies include it as part of their technical rounds for frontend and full-stack developer roles. Organizations like TCS, Infosys, Wipro, Cognizant, and Capgemini frequently ask AJAX-related questions to check whether candidates can build dynamic, responsive, and efficient web pages. This guide includes commonly asked AJAX interview questions with clear explanations to help freshers and job seekers strengthen their web development fundamentals. These questions will improve your preparation for placement interviews, coding rounds, and real-time project discussions.
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121. How can I get the ASCII code for a character in C#?
Casting the char to an int will give you the ASCII value: char c = 'f'; System.Console.WriteLine((int)c); or for a character in a string: System.Console.WriteLine((int)s[3]); The base class libraries also offer ways to do this with the Convert class or Encoding classes if you need a particular encoding.
122. Is there an equivalent to the instanceof operator in Visual J++?
C# has the is operator:
expr is type
123. How do I create a Delegate/MulticastDelegate?
C# requires only a single parameter for delegates: the method address. Unlike other languages, where the programmer must specify an object reference and the method to invoke, C# can infer both pieces of information by just specifying the method's name. For example, let's use System.Threading.ThreadStart: Foo MyFoo = new Foo(); ThreadStart del = new ThreadStart(MyFoo.Baz); This means that delegates can invoke static class methods and instance methods with the exact same syntax!
124. How can you sort the elements of the array in descending order?
By calling Sort() and then Reverse() methods.
125. How do you debug an ASP.NET Web application?
Attach the aspnet_wp.exe process to the DbgClr debugger.
126. How do you mark a method obsolete?
Assuming you've done a "using System;": [Obsolete]
public int Foo() {...}
or [Obsolete("This is a message describing why this method is obsolete")]
public int Foo() {...}
Note: The O in Obsolete is capitalized.
127. How is the DLL Hell problem solved in .NET?
Assembly versioning allows the application to specify not only the library it needs to run (which was available under Win32), but also the version of the assembly
128. What are the ways to deploy an assembly?
An MSI installer, a CAB archive, and XCOPY command.
129. Why does DllImport not work for me?
All methods marked with the DllImport attribute must be marked as public static extern.
130. What is a delegate?
A delegate object encapsulates a reference to a method. In C++ they were referred to as function pointers.