When it comes to object-oriented programming in C++, two of the most fundamental concepts are struct and class. These two keywords are often used interchangeably, but there are some key distinctions that are important to understand in order to write efficient and effective code.
First, let's start with the basics. Both struct and class are used to define custom data types, also known as user-defined data types. This means that instead of just using the built-in data types like int or float, we can create our own data types that have specific characteristics and behaviors.
Structs in C++ are used to group together related data items. They are essentially a collection of variables that can have different data types. For example, we can create a struct called "book" that has variables for the title, author, and publication date. Structs can also have functions, but these functions are limited to simple operations and cannot have access modifiers like private or public.
On the other hand, classes are more complex data structures that can contain both variables and functions. In addition, classes have access modifiers that allow us to control the level of access to these variables and functions. This means that we can make some variables and functions private, only accessible within the class itself, and others public, accessible from outside the class.
Another key difference between structs and classes is in how they handle data. Structs use the concept of pass by value, which means that when we pass a struct as an argument to a function, a copy of the struct is made and any changes made to the copy will not affect the original struct. Classes, on the other hand, use pass by reference, which means that when we pass a class as an argument, we are passing a pointer to the original class, and any changes made to the class will affect the original object.
This difference in data handling also affects how structs and classes are used in memory. Structs are allocated memory on the stack, while classes are allocated memory on the heap. This means that structs are generally faster to access and manipulate, but classes offer more flexibility and can be dynamically allocated and deallocated.
So, when should we use structs and when should we use classes? As a general rule, structs are best used for simple data structures that do not require complex functions or access modifiers. They are also useful for performance-critical applications where speed and memory usage are important. Classes, on the other hand, are more suitable for larger and more complex data structures that require more control and flexibility.
In conclusion, while struct and class may seem similar on the surface, they have distinct differences that make them suitable for different purposes. Structs are simpler and more limited, while classes offer more functionality and control. By understanding these distinctions, we can make informed decisions on when to use each keyword in our C++ programs.
