Understanding the Differences Between Class and Structure
When it comes to programming in object-oriented languages, two of the most commonly used constructs are classes and structures. While both of these constructs can be used to create objects, they do have their own unique characteristics and purposes. In this article, we will discuss the differences between classes and structures, and help you understand when to use one or the other.
Definition of Class and Structure
A class is a blueprint for creating objects. It defines the properties and methods that an object will have. The properties define the characteristics of the object, while the methods define its behavior.
On the other hand, a structure is a simple data type that groups together related data. It doesn’t have any behavior or methods associated with it, only properties.
Usage of Class and Structure
The main difference between classes and structures lies in their intended usage. Classes are used to create objects that have behavior and methods associated with them. For example, a car class might have properties like make, model, and year, as well as methods like start_engine() and stop_engine().
Structures, on the other hand, are used to group together related data that doesn’t need to have any behavior associated with it. For example, a struct that represents a date might have properties like year, month, and day.
Memory Allocation and Performance
Another key difference between classes and structures is how they are stored in memory. When you create an object from a class, memory is allocated on the heap. This means that the object will remain in memory until it is explicitly deleted.
Structures, on the other hand, are stored in memory on the stack. This means that they are automatically deleted when the function that created them exits. This makes structures more lightweight and efficient than classes, making them a great choice for simple data types that don’t require any behavior.
Inheritance and Polymorphism
One of the biggest advantages of classes over structures is that they support inheritance and polymorphism. Inheritance allows you to create a new class that inherits properties and methods from an existing class, while polymorphism allows you to create multiple classes that share the same interface, but have different implementations.
Structures do not support inheritance, and since they don’t have any methods or behavior, they don’t need to support polymorphism.
Conclusion
In summary, while both classes and structures are used to create objects in object-oriented programming, they have their own unique characteristics and intended uses. If you need to create an object that has behavior and methods associated with it, you should use a class. If you only need to group together related data that doesn’t require behavior or methods, you should use a structure. By understanding the differences between these constructs, you can choose the right one for each situation, and write more efficient and effective code.
Table difference between class and structure
| Feature | Class | Structure |
|———|——-|———–|
| Purpose | To create objects | To group related data |
| Main characteristic | Objects created from classes have behaviors (methods) in addition to properties (attributes) | Only contains related properties (attributes) |
| Syntax | Identified by the keyword class, followed by the class name| Identified by the keyword struct, followed by the structure name |
| Inheritance | Supports single and multiple inheritance by using the keyword “extends” | Does not support inheritance in traditional sense, but can be simulated using interfaces |
| Example | `class Car {`
` String make;`
` String model;`
`}` | `struct Student {`
` int roll_no;`
` char name[50];`
` float marks;`
`};` |