C++ Structs

The C++ struct (short for “structure”) is a composite data type that allows you to group together variables of different data types under a single name. Unlike classes, which can have member functions and support access control keywords (private, protected, public), structs are typically used for simple data structures where the focus is on grouping related data rather than encapsulating behavior.

Here’s how you define and use a struct in C++:

struct Point {
    int x;
    int y;
};

In this example, we’ve defined a struct called Point with two data members: x and y. Each instance of the Point struct can hold two integers to represent a point’s coordinates.

You can create instances (objects) of the struct and access its members as follows:

Point p1;  // Declare an instance of the Point struct
p1.x = 5;  // Access and set the x coordinate
p1.y = 10; // Access and set the y coordinate

// Access and print the coordinates
std::cout << "x: " << p1.x << ", y: " << p1.y << std::endl;

Key points about C++ structs:

1. Member Variables: A struct defines its member variables inside its body. These variables can have different data types and are accessible directly without the need for accessor methods (getters and setters).
2. Public Access: By default, all members of a struct are public, which means they can be accessed and modified from outside the struct. There’s no access control like private or protected in classes.
3. Initialization: You can initialize struct members when declaring a struct variable.

 Point p2 = {3, 7}; // Initializing members at the time of declaration

4. Array of Structs: You can create arrays or collections of structs to represent multiple instances of the same structure.

 Point points[10]; // Array of 10 Point structs
 points[0].x = 1;
 points[0].y = 2;

5. Passing Structs to Functions: You can pass structs to functions by value or by reference, just like any other data type.

 void printPoint(const Point& p) {
     std::cout << "x: " << p.x << ", y: " << p.y << std::endl;
 }

6. C++ vs. C: In C, structs are primarily used for data grouping, while classes are used for encapsulating data and behavior. In C++, structs and classes are quite similar, but classes have access control features, whereas structs have public members by default.
7. Naming Conventions: Typically, struct names are in TitleCase, similar to class names. Member variables of structs often follow a lowerCamelCase naming convention.

Structs are a simple and effective way to group related data together in C++, making them a useful tool for representing objects with just data and no behavior. They are commonly used in scenarios where data needs to be aggregated and passed around as a single unit.