A class constructor is a special method in object-oriented programming that is automatically called when an instance (object) of the class is created. The primary purpose of a constructor is to initialize the newly created object.
In many programming languages, including Python, C++, and Java, constructors have specific syntax and behavior. Let's look at examples in a few popular languages:

Python
In Python, the constructor method is defined using the init method. This method is called when an object is instantiated.

Java
In Java, the constructor has the same name as the class and does not have a return type, not even void.

JavaScript
In JavaScript, a class constructor is a special method used for creating and initializing an object created within a class. The constructor method is called automatically when a new instance of the class is created using the new keyword.