C# Classes and Objects
Classes and Objects
You learned from the previous chapter that C# is an object-oriented programming language.
Everything in C# is associated with classes and objects, along with its attributes and methods. For example: in real life, a car is an object. The car has attributes, such as weight and color, and methods, such as drive and brake.
A Class is like an object constructor, or a "blueprint" for creating objects.
Create a Class
To create a class, use the class keyword:
Create a class named "Car" with a variable color:
class Car
{
string color = "red";
}When a variable is declared directly in a class, it is often referred to as a field (or attribute).
It is not required, but it is a good practice to start with an uppercase first letter when naming classes. Also, it is common that the name of the C# file and the class matches, as it makes our code organized. However it is not required (like in Java).
Create an Object
An object is created from a class. We have already created the class named
Car,
so now we can use this to create objects.
To create an object of Car,
specify the class name, followed by the object name, and use the keyword new:
Example
Create an object called "myObj" and use
it to print the value of
color:
class Car
{
string color = "red";
static void Main(string[] args)
{
Car myObj = new Car();
Console.WriteLine(myObj.color);
}
}Note that we use the dot syntax (.) to access variables/fields inside a class (myObj.color). You will learn more about
fields in the next chapter.
