A copy constructor is automatically invoked in object-oriented programming when a new object is created as a copy of an existing object. This typically occurs in scenarios such as passing an object by value to a function, returning an object from a function, or initializing a new object with another existing object. The copy constructor allows for the creation of a new instance that duplicates the state of the original object, ensuring that any dynamic resources are correctly managed.
when we create the object of that class
A constructor is a method that is invoked when an object is created. As to being mandatory, that really depends on the programming language; in the case of Java, each class must have a constructor, however, in many cases Java will automatically provide a default constructor, so you don't really need to program it.
Both are functions, i.e., places where you can write code. A constructor is simply a special method that is invoked automatically when an object is created.
There is no such thing as a constructor function in C++ (constructors have no return value, not even void, and cannot be called like regular functions). Constructors are invoked rather than called directly, either by declaring a static variable of the class type, or via the C++ new operator.
The base class constructor is invoked first when a subclass is instantiated, because the base class must be viable and consistent before the subclass constructor is fired.
The constructor.
The Class object is automatically created by the JVM when an object is created. The Class object provides information about the Class and is primarily used by the IDEs and factory classes. The method that is automatically called when an object is created is called a constructor. In Java, the constructor is a method that has the same name as the class.
bcoz constructor cant be invoked
When a constructor is invoked dynamically, the new operator allocates the required memory, initialises it according to the constructor, then returns a pointer to the allocation. The destructor is invoked by deleting the pointer. It wouldn't make any sense to return a pointer from a deletion.
Implicitly: (i.e., you do not code for it, but works as if you did)calling the no-argument constructor of the subclass, and there is no explicitly "redirect" codes.Explicitly:a constructor with base() / super() in the implementation, even that invoked constructor required some arguments.C# example: public SubClass(string whatever) : base() {//...}
It really depends on the programming language. In C and C++, all built-in types are initialised to zero when declared static, otherwise they are uninitialised. In Java, however, all data types are implemented as objects and are therefore initialised at the point of instantiation according to whichever constructor is invoked.
(a) A constructor is similar to a method, but it has exactly the same name as the class (including the combination of uppercase and lowercase letters). (b) It is placed inside the class definition. (c) The constructor is invoked automatically when you create an object based on that class. (d) To display a message, you can use the command System.out.println("Put message here")