A constructor is a function that is called when an object is created. A constructor is a function that takes a few arguments the type of object to be created, the initial state of the object, and the name of the class that will contain the object. When an object is created, it is passed to the constructor of the class that contains the object. A constructor can be used in many different ways. For example, a constructor can be used to initialize an array of objects or to initialize a variable that will be used by multiple objects. In these cases, it is important to use a constructor that takes only a few arguments.