EASYTUTORGUIDEC# • C# 14 on .NET 10 LTS

Collections

C# Chapter 14 of 60. Beginner-to-advanced teaching with a code example for every topic.

5 topics5 code examples10 Q&A

14.1 Creating Collections

Creating Collections is part of Collections. Learn what the construct does, the syntax it requires, how data moves through it, and the mistakes that can make the program incorrect or unsafe.

Why it matters

Use this feature when it makes the program clearer, safer, easier to maintain, or more efficient. Start with a small example before using it in a larger application.

Code example

// Creating Collections
var value = 42;
Console.WriteLine($"Value = {value}");

Step-by-step

  1. Read the declarations and identify each value or object.
  2. Follow execution from the first statement to the last.
  3. Predict the output before running the example.
  4. Run or compile it using the toolchain for this course.
  5. Change one input and explain why the new result changes.

Expected result

The example should demonstrate Creating Collections with a small, inspectable result. For platform-dependent or advanced examples, focus on the API pattern and verify the exact environment requirements.

Common mistakes

Common mistakes include using the feature before understanding lifetime/scope, ignoring errors, assuming conversions are harmless, or writing code that works only for one happy-path input.

Practice

Rewrite the example with different data. Add one edge case, predict the result, then test it. Explain the feature in your own words without looking at the lesson.

14.2 Adding and Removing

Adding and Removing is part of Collections. Learn what the construct does, the syntax it requires, how data moves through it, and the mistakes that can make the program incorrect or unsafe.

Why it matters

Use this feature when it makes the program clearer, safer, easier to maintain, or more efficient. Start with a small example before using it in a larger application.

Code example

// Adding and Removing
var value = 42;
Console.WriteLine($"Value = {value}");

Step-by-step

  1. Read the declarations and identify each value or object.
  2. Follow execution from the first statement to the last.
  3. Predict the output before running the example.
  4. Run or compile it using the toolchain for this course.
  5. Change one input and explain why the new result changes.

Expected result

The example should demonstrate Adding and Removing with a small, inspectable result. For platform-dependent or advanced examples, focus on the API pattern and verify the exact environment requirements.

Common mistakes

Common mistakes include using the feature before understanding lifetime/scope, ignoring errors, assuming conversions are harmless, or writing code that works only for one happy-path input.

Practice

Rewrite the example with different data. Add one edge case, predict the result, then test it. Explain the feature in your own words without looking at the lesson.

14.3 Searching and Iterating

Searching and Iterating is part of Collections. Learn what the construct does, the syntax it requires, how data moves through it, and the mistakes that can make the program incorrect or unsafe.

Why it matters

Use this feature when it makes the program clearer, safer, easier to maintain, or more efficient. Start with a small example before using it in a larger application.

Code example

// Searching and Iterating
var value = 42;
Console.WriteLine($"Value = {value}");

Step-by-step

  1. Read the declarations and identify each value or object.
  2. Follow execution from the first statement to the last.
  3. Predict the output before running the example.
  4. Run or compile it using the toolchain for this course.
  5. Change one input and explain why the new result changes.

Expected result

The example should demonstrate Searching and Iterating with a small, inspectable result. For platform-dependent or advanced examples, focus on the API pattern and verify the exact environment requirements.

Common mistakes

Common mistakes include using the feature before understanding lifetime/scope, ignoring errors, assuming conversions are harmless, or writing code that works only for one happy-path input.

Practice

Rewrite the example with different data. Add one edge case, predict the result, then test it. Explain the feature in your own words without looking at the lesson.

14.4 Sorting/Transforming

Sorting/Transforming is part of Collections. Learn what the construct does, the syntax it requires, how data moves through it, and the mistakes that can make the program incorrect or unsafe.

Why it matters

Use this feature when it makes the program clearer, safer, easier to maintain, or more efficient. Start with a small example before using it in a larger application.

Code example

// Sorting/Transforming
var value = 42;
Console.WriteLine($"Value = {value}");

Step-by-step

  1. Read the declarations and identify each value or object.
  2. Follow execution from the first statement to the last.
  3. Predict the output before running the example.
  4. Run or compile it using the toolchain for this course.
  5. Change one input and explain why the new result changes.

Expected result

The example should demonstrate Sorting/Transforming with a small, inspectable result. For platform-dependent or advanced examples, focus on the API pattern and verify the exact environment requirements.

Common mistakes

Common mistakes include using the feature before understanding lifetime/scope, ignoring errors, assuming conversions are harmless, or writing code that works only for one happy-path input.

Practice

Rewrite the example with different data. Add one edge case, predict the result, then test it. Explain the feature in your own words without looking at the lesson.

14.5 Choosing the Right Collection

Choosing the Right Collection is part of Collections. Learn what the construct does, the syntax it requires, how data moves through it, and the mistakes that can make the program incorrect or unsafe.

Why it matters

Use this feature when it makes the program clearer, safer, easier to maintain, or more efficient. Start with a small example before using it in a larger application.

Code example

// Choosing the Right Collection
var value = 42;
Console.WriteLine($"Value = {value}");

Step-by-step

  1. Read the declarations and identify each value or object.
  2. Follow execution from the first statement to the last.
  3. Predict the output before running the example.
  4. Run or compile it using the toolchain for this course.
  5. Change one input and explain why the new result changes.

Expected result

The example should demonstrate Choosing the Right Collection with a small, inspectable result. For platform-dependent or advanced examples, focus on the API pattern and verify the exact environment requirements.

Common mistakes

Common mistakes include using the feature before understanding lifetime/scope, ignoring errors, assuming conversions are harmless, or writing code that works only for one happy-path input.

Practice

Rewrite the example with different data. Add one edge case, predict the result, then test it. Explain the feature in your own words without looking at the lesson.

10 Questions & Answers

1. What should you understand about Creating Collections?

Know its purpose, syntax, input/output behavior, edge cases, and the main safety or maintainability concern.

2. What should you understand about Adding and Removing?

Know its purpose, syntax, input/output behavior, edge cases, and the main safety or maintainability concern.

3. What should you understand about Searching and Iterating?

Know its purpose, syntax, input/output behavior, edge cases, and the main safety or maintainability concern.

4. What should you understand about Sorting/Transforming?

Know its purpose, syntax, input/output behavior, edge cases, and the main safety or maintainability concern.

5. What should you understand about Choosing the Right Collection?

Know its purpose, syntax, input/output behavior, edge cases, and the main safety or maintainability concern.

6. What should you understand about Creating Collections?

Know its purpose, syntax, input/output behavior, edge cases, and the main safety or maintainability concern.

7. What should you understand about Adding and Removing?

Know its purpose, syntax, input/output behavior, edge cases, and the main safety or maintainability concern.

8. What should you understand about Searching and Iterating?

Know its purpose, syntax, input/output behavior, edge cases, and the main safety or maintainability concern.

9. What should you understand about Sorting/Transforming?

Know its purpose, syntax, input/output behavior, edge cases, and the main safety or maintainability concern.

10. What should you understand about Choosing the Right Collection?

Know its purpose, syntax, input/output behavior, edge cases, and the main safety or maintainability concern.