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A constructor creates an Object of the class that it is in by initializing all the instance variables and creating a place in memory to hold the Object. It is always used with the keyword new and then the Class name.
For instance, new String(); constructs a new String object.
Sometimes in a few classes you may have to initialize a few of the variables to values apart from their predefined data type specific values. If java initializes variables it would default them to their variable type specific values. For example you may want to initialize an integer variable to 10 or 20 based on a certain condition, when your class is created. In such a case you cannot hard code the value during variable declaration. such kind of code can be placed inside the constructor so that the initialization would happen when the class is instantiated.
Properties:
1. You need not code them explicitly. Java will automatically place a default constructor
2. You can pass arguments to the constructor
3. They can return only an object of type of that class
4. They can be made private
5. They would be executed always (Everytime a class is instantiated)
Wiki User
∙ 15y ago
Wiki User
∙ 11y ago1)It has same name as that of class
2)It does not return any data type even void.
Wiki User
∙ 6y agoA constructor is a class initialiser; it allows us to initialise the class data members with appropriate values for the class and/or values chosen by the user, at the point of instantiation.
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What is a constructor and its mandatory to use constructor in a class?
Constructor is a special block of code similar to the method that is used to initialize the state of objects. If you do not define a constructor in a class, Java compiler automatically put a default constructor in the class.
Default constructor in java?
If you don't type a constructor into your class code, a default constructor will be automatically generated by the compiler. The default constructor is ALWAYS a no-arg constructor. (Obviously the compiler has no clue what all arguments you might want for your class. So it takes the safe way out with a no argument constructor) A no-arg constructor is not necessarily the default (i.e., compiler-supplied) constructor, although the default constructor is always a no-arg constructor. The default constructor is the one the compiler provides! While the default constructor is always a no-arg constructor, you're free to put in your own no-arg constructor.
Can you declare and define the constructor within class?
Yes, you can declare and define the constructor within a class. A constructor is a special member function of a class that is automatically called when an object of the class is created. It is used to initialize the object's data members. The constructor can be declared and defined within the class definition or can be defined outside the class definition using the scope resolution operator (::).
What is the name of the special member function which is automatically called during creation of each class object?
The constructor. The constructor instantiates the object, and can optionally take parameters and has an optional initialization phase. It has no return type, and has the same name as the class itself. The constructor can be overloaded. It cannot be virtual or constant.
Why Java always provides a default constructor to class when you use another constructor default constructor remove?
Classes in Java inherit constructors from their parent classes. If you don't explicitly define a parent class, then Object is used, which has only the default empty constructor. That "default" constructor is only there when defined by the parent class, so classes which do not have a no-argument constructor will not allow subclasses to automatically use it. This is implemented this way because of the special nature of constructors. Java could not always provide a default constructor because it could not guarantee that all class members would be properly created or initialized.
What is constructor in cplusplus?
A constructor is a special member function which have same name as the class name.`
Why constructor rather than classes in java?
Constructor is not an alternative to class. In Java, you create classes; the classes contain methods - including the constructor, which can be viewed as a special method. If you want to have a constructor, you need a class that surrounds it, so it's not one or the other.
What is the diffferent between method and constructor?
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.
What is the meaning of copy constructor?
The meaning of copy constructor is a special programmer of the C++ language that copys existing coding projects and enhances or makes them better projects.
What are the properties of special properties?
Special properties are unusual properties a mineral may have that most minerals don't.
Differene betwee constructor overloading same as method overloading?
A constructor is just a special form of a method. You can overload constructors in the exact same way as you can overload any other method.
Can you declare and define the constructor within class?
Yes, you can declare and define the constructor within a class. A constructor is a special member function of a class that is automatically called when an object of the class is created. It is used to initialize the object's data members. The constructor can be declared and defined within the class definition or can be defined outside the class definition using the scope resolution operator (::).
Default constructor in java?
If you don't type a constructor into your class code, a default constructor will be automatically generated by the compiler. The default constructor is ALWAYS a no-arg constructor. (Obviously the compiler has no clue what all arguments you might want for your class. So it takes the safe way out with a no argument constructor) A no-arg constructor is not necessarily the default (i.e., compiler-supplied) constructor, although the default constructor is always a no-arg constructor. The default constructor is the one the compiler provides! While the default constructor is always a no-arg constructor, you're free to put in your own no-arg constructor.
What is the name of the special member function which is automatically called during creation of each class object?
The constructor. The constructor instantiates the object, and can optionally take parameters and has an optional initialization phase. It has no return type, and has the same name as the class itself. The constructor can be overloaded. It cannot be virtual or constant.
What is the definition of special properties?
The definition of special properties are the unique features of a substance. They are commonly derived from other intrinsic and extrinsic properties.
Why Java always provides a default constructor to class when you use another constructor default constructor remove?
Classes in Java inherit constructors from their parent classes. If you don't explicitly define a parent class, then Object is used, which has only the default empty constructor. That "default" constructor is only there when defined by the parent class, so classes which do not have a no-argument constructor will not allow subclasses to automatically use it. This is implemented this way because of the special nature of constructors. Java could not always provide a default constructor because it could not guarantee that all class members would be properly created or initialized.
What are some special properties of sulphur?
Some of the sulfur special properties are odorless, tasteless and its color
