Lecture 5: Visual Studio and C++ Basics

Creating a C++ Project in Visual Studio

Steps to Create a Project:

1. Launch Visual Studio 2022.
2. Select Create a new project.
3. Choose the Empty Project template for C++.
4. Configure the project:
   • Enter a Project name (e.g., Project_NTCU).
   • Select the Location to save the files.
5. Click Create.

Steps to Add a Source File:

1. In the Solution Explorer pane, right-click the Source Files folder.
2. Select Add > New Item....
3. In the dialog box, name the file with a .cpp extension (e.g., first_program.cpp).
4. Click Add.

Running and Managing the Project

Comparison of Execution Modes:

Action	Shortcut	Debugger Attached	Console Stays Open?	Use Case
Start Debugging	F5	Yes	No (by default)	To find and fix bugs.
Start Without Debugging	Ctrl + F5	No	Yes	To run the program and view the final output.

NOTE

To prevent the console from closing immediately when using F5, navigate to Tools > Options > Debugging.
Uncheck "Automatically close the console when debugging stops."

Resolving main() Function Conflicts: A project can only have one main() function in the build. To keep multiple files with main() in a project, you must exclude all but one from the build process.

Steps to Exclude a File from Build:

1. In Solution Explorer, right-click the .cpp file to exclude.
2. Select Properties.
3. Set Configuration to Active (Debug) and Platform to x64.
4. Navigate to Configuration Properties -> General.
5. Find the Excluded From Build option and change its value from No to Yes.
6. Click Apply, then OK.

Visual Studio Project Structure

File Extension / Name	Description
*.cpp	The source file containing the actual C++ code (functions, main(), logic).
*.sln (Solution File)	Organizes and manages one or more projects. Contains references to project files and build configurations.
*.vcxproj (Project File)	An XML file containing all project settings, including source files, compiler options, and build instructions.
*.vcxproj.filters	Controls the visual organization of files in Solution Explorer (e.g., "Source Files" folder). Does not affect the build.
*.vcxproj.user	Stores user-specific settings like debugging options. Not typically shared.

Core C++ Syntax

• Comments: Used to explain code; they are ignored by the compiler.
  • Single-line: // This is a comment
  • Multi-line: /* This is a multi-line comment */
• New Lines: Can be created using the \n escape sequence or endl.
  • cout << "Hello World!" << "\n";
  • cout << "Hello World!" << endl;

Common Escape Sequences:

Sequence	Description
\n	Inserts a new line.
\t	Inserts a horizontal tab.
\\	Inserts a backslash character (\).
\"	Inserts a double-quote character (").

Variables and Data Types

• Variable: A container for storing a data value. It must be declared with a specific data type.
• Declaration: Defining a variable without assigning a value.
  • Example: int x;
• Assignment: Giving a value to a previously declared variable.
  • Example: x = 20;
• Initialization: Declaring a variable and assigning it a value in one step.
  • Example: int count = 0;

Classification of C++ Data Types:

1. Primary: Basic types like int, char, float, bool.
2. Derived: Types derived from primary types, like Array, Function, Pointer.
3. User-Defined: Types created by the programmer, like Class, Structure, Enum.

Basic Data Types:

Data Type	Description	Size
int	Stores whole numbers without decimals.	2 or 4 bytes
float	Stores fractional numbers. Sufficient for 6-7 decimal digits.	4 bytes
double	Stores fractional numbers. Sufficient for up to 15 decimal digits.	8 bytes
char	Stores a single character/letter/number or ASCII value. Values are enclosed in single quotes (e.g., 'A').	1 byte
string	Stores a sequence of characters (text). Values are enclosed in double quotes (e.g., "Hello"). Requires #include <string>.	24 to 32 bytes
boolean	Stores one of two states: true or false.	1 byte

• Scientific Numbers: Floating-point numbers can be represented with an "e" or "E" to indicate the power of 10.
  • Example: float f1 = 27E3; is equivalent to 27000.
• ASCII Values: The char type can use ASCII decimal values to represent characters.
  • Example: char myVar = 65; will store the character 'A'.

Operators

Arithmetic Operators

Operator	Name	Example
+	Addition	x + y
-	Subtraction	x - y
*	Multiplication	x * y
/	Division	x / y
%	Modulus (remainder)	x % y
++	Increment (increases by 1)	++x
--	Decrement (decreases by 1)	--x

Assignment Operators

Operator	Example	Equivalent To
=	x = 9	x = 9
+=	x += 9	x = x + 9
-=	x -= 9	x = x - 9
*=	x *= 9	x = x * 9
/=	x /= 9	x = x / 9
%=	x %= 9	x = x % 9
&=	x &= 9	x = x & 9
|=	x |= 9	x = x | 9
^=	x ^= 9	x = x ^ 9
>>=	x >>= 9	x = x >> 9
<<=	x <<= 9	x = x << 9

Comparison Operators

Used to compare two values. They return 1 (true) or 0 (false).

Operator	Name	Example
==	Equal to	x == y
!=	Not equal to	x != y
>	Greater than	x > y
<	Less than	x < y
>=	Greater than or equal to	x >= y
<=	Less than or equal to	x <= y

Logical Operators

Used to determine the logic between variables or values.

Operator	Name	Description	Example
&&	Logical AND	Returns true if both statements are true.	x < 10 && x > 5
|	Logical OR	Returns true if one of the statements is true.	x < 5 | x > 10
!	Logical NOT	Reverses the result; returns false if the result is true.	!(x < 5 && x < 10)

String Manipulation

• Concatenation: Strings can be joined using the + operator or the append() method.
  • string fullName = firstName + lastName;
  • string fullName = firstName.append(lastName);
• Combining Numbers and Strings: It is an error to directly add a number to a string. The number must first be converted to a string using to_string().
  • string result = "Age: " + to_string(25);

User Input

The cin object is used to get user input from the keyboard.

• Example:

Operator Precedence

The order in which C++ evaluates operators in an expression, from highest to lowest priority:

1. () (Parentheses)
2. *, /, % (Multiplication, Division, Modulus)
3. +, - (Addition, Subtraction)
4. >, <, >=, <= (Comparison)
5. ==, != (Equality)
6. && (Logical AND)
7. \|\| (Logical OR)
8. = (Assignment)