Зміст курсу

C# Beyond Basics

1. Additional Structures & File Handling

What are Lists?Practicing List Declaration List Methods What are Dictionaries?Practicing Dictionaries Reading Files using StreamReader Reading Files using File Methods Writing Files Error Handling Practicing Error Handling

2. Structs & Enumerators

What are Structs?Defining & Using a Structure Practicing Structs Structs with Other Data Structures Struct Methods Correctly Accessing Fields in Struct Methods Practicing Methods Struct Constructors Practicing Constructors Enumerators Practicing Enumerator

3. Introduction to Object-Oriented Programming (OOP)

What is Object-Oriented Programming?Defining Classes Practice: Creating Classes Class Objects Class Objects vs Struct Objects Practice: Objects Class Methods Practice: Methods Class Constructors Practice: Constructors

4. OOP Essentials

Derived Classes Derived Classes Practice Common Access Modifiers Access Modifiers Practice The `static` Keyword Practicing `static` Keyword Method Overloading Method Overloading Practice

5. OOP Principles

What are the Principles of OOP?Inheritance Practicing Inheritance Polymorphism Practicing Polymorphism Encapsulation Encapsulation Practice Abstraction Abstraction Practice What's Next?

C# Beyond Basics

Error Handling

You might have come across the term runtime error in previous chapters. A runtime error is an error which occurs while the program is running - hence the name "runtime" error.

Usually when a runtime error occurs, the program crashes or stops responding.

The compiler can help us by pointing out most of the errors in our code but runtime errors are mostly unpredictable and often depend on uncertain parameters.

For-example, in case the file path passed into StreamReader is invalid or does not exist, it will give a runtime error and the program will crash. Therefore, we often put such dangerous code into try-catch blocks to try some code, and in case it fails, we catch and deal with the error instead of causing the program to crash.

Following is the syntax of the try-catch block:

index.cs

Here Exception is a keyword which represents the datatype Exception.

Example:

index.cs

We can omit the (Exception error) part from the catch statement if we're not using error.

Following are some common cases where a runtime error can occur:

Division By Zero

index.cs

Invalid Index of an Array or a List

index.cs

Key Not Found (for Dictionaries):

index.cs

The "finally" Block

There's also an option code block called finally which is executed after the catch block is executed:

index.cs

1. What will be the output of the following program?

2. In C#, what is the purpose of the `finally` block?

3. Which of the following statements is true regarding the `try-catch` block in C#?

What will be the output of the following program?

Виберіть правильну відповідь

Index Error

2 4 6 8 10

Nothing

In C#, what is the purpose of the finally block?

Виберіть правильну відповідь

To declare variables

To execute code regardless of whether an exception is thrown or not

To catch exceptions

To terminate the program

Which of the following statements is true regarding the `try-catch` block in C#?

Виберіть кілька правильних відповідей

The try block must always be followed by a catch block.

The catch block is optional.

The try block is optional.

The finally block is optional.

Все було зрозуміло?

Секція 1. Розділ 9

Зміст курсу

C# Beyond Basics

1. Additional Structures & File Handling

2. Structs & Enumerators

3. Introduction to Object-Oriented Programming (OOP)

4. OOP Essentials

Derived Classes Derived Classes Practice Common Access Modifiers Access Modifiers Practice The `static` Keyword Practicing `static` Keyword Method Overloading Method Overloading Practice

5. OOP Principles

What are the Principles of OOP?Inheritance Practicing Inheritance Polymorphism Practicing Polymorphism Encapsulation Encapsulation Practice Abstraction Abstraction Practice What's Next?

C# Beyond Basics

Error Handling

You might have come across the term runtime error in previous chapters. A runtime error is an error which occurs while the program is running - hence the name "runtime" error.

Usually when a runtime error occurs, the program crashes or stops responding.

The compiler can help us by pointing out most of the errors in our code but runtime errors are mostly unpredictable and often depend on uncertain parameters.

Following is the syntax of the try-catch block:

index.cs

Here Exception is a keyword which represents the datatype Exception.