Initializing Objects with Constructors

• When an object of a class is created, its instance variables are initialized by default.

• Each class can provide a constructor that initializes an object of a class when the object is created.

• Java requires a constructor call for every object that is created.

• Keyword new requests memory from the system to store an object, then calls the corresponding class’s constructor to initialize the object.

• A constructor must have the same name as the class.

• By default, the compiler provides a default constructor with no parameters in any class that does not explicitly include a constructor.

  • Instance variables are initialized to their default values.

• Can provide your own constructor to specify custom initialization for objects of your class.

• A constructor’s parameter list specifies the data it requires to perform its task.

• Constructors cannot return values, so they cannot specify a return type.

• Normally, constructors are declared public.

• If you declare any constructors for a class, the Java compiler will not create a default constructor for that class.