java constructor not called in main class

#Java constructor not called in main class code#

There are the following characteristics or features of constructor in Java. If somebody asks that I want to create a class but nobody should instantiate it, you can say “make the constructor private”.

If you apply a private access modifier with a java constructor, you cannot create an object of that class in other classes. By mistake, if you apply any other modifiers with constructor except these three access modifiers, you will get a compile-time error. Non-access modifiers cannot be applied with constructors. These are called access modifiers in Java. A constructor can be declared (optionally) as public, protected, and private. Public is an access modifier that indicates that other classes can access the constructor. Here, Rectangle is a class name that must be the same as the name of class that contains constructor.

#Java constructor not called in main class code#

The following example code defines a constructor in the class. Here, we can initialize the values of instance variables. Constructor body which is a block of statements. The general syntax to declare a constructor in Java is as: Access modifiers_name class_name(formal_parameter_list) // constructor header. Generally, we declare a constructor inside the public section of the class by the following syntax so that we can create its object in any function. If we try to create an object of the class without specifying any constructor in the class, compiler automatically create a default constructor for us. It is automatically invoked when an instance of a class is created using the new operator.Ĭonstructors can also accept arguments like methods and can be overloaded. Java constructor can perform any action but specially designed to perform initializing actions, such as initializing the instance variables with legal initial values.Ī constructor within a class allows constructing the object of the class at runtime. The sole purpose of a constructor is to perform the initialization of data fields of an object in the class. In other words, a constructor is a special member function of a class used to initialize instance variables of a class. A constructor in Java is a block of code, syntactically similar to a method that is used to initialize the state of an object in a class.