1: Microsoft Tutorialノート

What youcan learn through this module

• Write your first lines of C# code.
• Use two different techniques to print a message as output.
• Diagnose errors when code is incorrect.
• Identify different C# syntax elements like operators, classes, and methods.

What C# allows you to build

he C# programming language allows you to build many types of applications, like:

• Business applications to capture, analyze, and process data
• Dynamic web applications that can be accessed from a web browser
• Games, both 2D and 3D
• Financial and scientific applications
• Cloud-based applications
• Mobile applications

Hello World

Console.WriteLine("Hello World!");

Display a new message

// Console.WriteLine("Hello World!");

Console.Write("Congratulations!");
Console.Write(" ");
Console.Write("You wrote your first lines of code.");

結果：

Congratulations! You wrote your first lines of code.

TIP: The difference between Console.Write and Console.WriteLine

Console.WriteLine

To print an entire message to the output console, you used the first technique, Console.WriteLine(). At the end of the line, it added a line feed similar to how to create a new line of text by pressing Enter or Return.

Console.Write

To print to the output console, but without adding a line feed at the end, you used the second technique, Console.Write(). So, the next call to Console.Write() prints another message to the same line.

Let’s try make 2 lines

This is the first line.
This is the second line.

上記のように出したい場合：

Console.WriteLine("This is the first line.");

Console.Write("This is ");
Console.Write("the second ");
Console.Write("line.");

Learn how it works

What is compilation

A special program called a compiler converts your source code into a different format that the computer’s central processing unit (CPU) can execute. When you used the green Run button in the previous unit, the code you wrote was first compiled, then executed.

Why does code need to be compiled? Although most programming languages seem cryptic at first, they can be more easily understood by humans than the computer’s preferred language. The CPU understands instructions that are expressed by turning thousands or millions of tiny switches either on or off. Compilers bridge these two worlds by translating your human-readable instructions into a computer-understandable set of instructions.

Waht is syntax(構文)?

The rules for writing C# code is called syntax. Just like human languages have rules regarding punctuation and sentence structure, computer programming languages also have rules. Those rules define the keywords and operators of C# and how they are put together to form programs.

When you wrote code into the .NET Editor, you may have noticed subtle changes to the color of different words and symbols. Syntax highlighting is a helpful feature that you’ll begin to use to easily spot mistakes in your code that don’t conform to the syntax rules of C#.

参考

• Microsoft training: Write your first C# code