Constructors
A constructor is a special method that is used to initialize objects. The advantage of a constructor, is that it is called when an object of a class is created. It can be used to set initial values for fields:
Example
Create a constructor:
// Create a Car class class Car { public string model; // Create a field // Create a class constructor for the Car class public Car() { model = "Mustang"; // Set the initial value for model } static void Main(string[] args) { Car Ford = new Car(); // Create an object of the Car Class (this will call the constructor) Console.WriteLine(Ford.model); // Print the value of model } } // Outputs "Mustang"
Note that the constructor name must match the class name, and it cannot have a return type (like void
or int
).
Also note that the constructor is called when the object is created.
All classes have constructors by default: if you do not create a class constructor yourself, C# creates one for you. However, then you are not able to set initial values for fields.
Constructors save time! Take a look at the last example on this page to really understand why.