Welcome to "Mastering C# Strings: Top 15 Interview Questions Answered"!

In this comprehensive video, we delve deep into the world of C# strings, covering essential concepts and addressing common interview questions that you're likely to encounter in your C# programming journey.

Strings are fundamental in C# programming, serving as the backbone for text manipulation and data representation. Understanding how to effectively work with strings is crucial for any C# developer, whether you're a beginner or an experienced professional.

Overview

In this video, we've curated a list of the top 15 interview questions specifically focusing on C# strings. Each question is meticulously crafted to test your knowledge and understanding of string manipulation, concatenation, formatting, and more.

Key Topics Covered

1. What is a string in C#?

   • A string is a sequence of characters used to represent text in C#.

2. How are strings represented internally in C#?

   • Strings in C# are represented as objects of the System.String class and stored as Unicode characters.

3. How is a string variable represented in memory?

   • String variables are reference types, pointing to an object in the managed heap.

4. Concept of immutability in C# strings?

   • Strings in C# are immutable, meaning once created, their value cannot be changed.

5. Difference between string and StringBuilder in C# with advantages?

   • StringBuilder is a mutable string class that provides better performance for repeated modifications.

6. String Intern concept in C#?

   • String interning is a method of storing only one copy of each distinct string value, which must be immutable.

7. String pooling concept in C#? (interlinked to string intern)

   • String pooling refers to the reuse of immutable string instances to save memory.

8. Concept of string interpolation in C#?

   • String interpolation allows embedding expressions within string literals using a $ prefix.

9. Escape characters/sequences in C# strings?

   • Escape characters, like \n for newline, allow special characters to be included in strings.

10. Different ways to concatenate strings in C#?

    • Concatenate strings using +, Concat, interpolation, Join, or StringBuilder.

11. Difference between == operator and Equals() & ReferenceEquals() method?

    • == compares values, Equals() compares content, and ReferenceEquals() compares references.

12. Convert a string to uppercase or lowercase in C# with memory implications?

    • Methods like ToUpper() and ToLower() create new string instances due to string immutability.

13. string.IsNullOrEmpty() vs string.IsNullOrWhiteSpace() method?

    • IsNullOrEmpty checks for null or empty strings, while IsNullOrWhiteSpace also checks for whitespace.

14. Important string functions: Split, Replace, Substring, IndexOf, LastIndexOf, and Trim?

    • Key string functions include splitting strings, replacing substrings, extracting substrings, finding characters, and trimming spaces.

15. StringComparison enumeration and its usage?

    • StringComparison specifies rules for string comparison, such as culture and case sensitivity.

Whether you're preparing for an interview or looking to strengthen your C# skills, this video will provide you with valuable insights and practical knowledge. Dive in and master the intricacies of C# strings with us!