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Of course constructors can receive values as parameters, there are not any restriction about it. An constructor is a special method executed when we instanted an object (we create an object with the 'new' operator) and as a method it can receive any kind of parameter:
public MyConstructor (int value1, int value2){
//do something with the values
}
public MyConstructor (MyObject obj){
//do something with the object
}
The above code shows two constructors (in java code) with different type and number of parameters.
The only restrictions are that they use the name of the class and have no return type.
What else can I help you with?
How is the default constructor equivalent to a constructor having default arguments?
Any constructor that can be invoked without explicitly passing any arguments is a default constructor. Note that there can be only one default constructor so there can only be one constructor where all arguments have default values or one constructor that has no arguments, but not both. A constructor where all arguments have default values is a useful means of combining two or more constructors into a single default constructor, thus reducing verbosity and code duplication.
Why there is the need of the constructor if you can assign the value to variables by the help of the methods ..?
A constructor is what allocates memory for an object. If you didn't call a constructor, you would have no object in which to assign values.
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.
How do you invoke the constructor function in c plus plus?
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.
What is a dynamic constructor?
dynamic constructor is a way to constructing an object based on the run type of some existing object. it basically uses standard virtual functions/polymorphism
Why you use constructor chaining?
Constructor ChainingWe know that constructors are invoked at runtime when you say new on some class type as follows:Lamborghini h = new Lamborghini();But what really happens when you say new Lamborghini() ? (Assume Lamborghini extends Car and Car extends Object.)1. Lamborghini constructor is invoked. Every constructor invokes the constructor of its superclass with an (implicit) call to super(),2. Car constructor is invoked (Car is the superclass of Lamborghini).3. Object constructor is invoked (Object is the ultimate superclass of all classes, so class Car extends Object even though you don't actually type "extends Object" into the Car class declaration. It's implicit.) At this point we're on the top of the hierarchy.4. Object instance variables are given their explicit values. By explicit values, we mean values that are assigned at the time the variables are declared, like "int x = 27", where "27" is the explicit value (as opposed to the default value) of the instance variable.5. Object constructor completes.6. Car instance variables are given their explicit values (if any).7. Car constructor completes.8. Lamborghini instance variables are given their explicit values (if any).9. Lamborghini constructor completes.
What are the properties of class in c plus plus?
A constructor is not a function. A function is a type, as specified by its return type, and must return a value of that type unless the type is void. A constructor does not return anything, not even void. The purpose of a constructor is to both allocate and initialise memory for an object of the type being constructed. If a valid object cannot be constructed for any reason, the constructor must throw an exception. If the object's class has no data members (attributes), the class does not require a constructor. This is typically the case for most abstract data types and base classes which are used purely as interfaces. Constructors differ from functions in that all constructors have an initialisation section that is used specifically to initialise non-static data members. The body of the constructor is rarely used except to perform initialisations that cannot be more easily performed by the initialisation section. A class may have more than one constructor to provide alternative methods of construction based upon the number and type of arguments supplied (if any). When no arguments are required or all arguments have default values then the constructor is known as the default constructor. If the constructor has only one argument the constructor is known as a conversion constructor (because the argument is converted to an object of the class). However, if the constructor argument is a constant reference to an object of the same class, then it is known as a copy constructor, and when the constructor argument is an rvalue reference, it is known as a move constructor. If copy and/or move constructors are provided for a class, the equivalent assignment operators should also be provided for that class. All other constructors are known as user-defined constructors.
How does constructor work?
First line in any constructor has to be either super() or this() not both. If any constructor does not contain either of super() and this(), compiler adds super(). When any constructor is called before excuting the code of the constructor, if it founds this(), it will call another constructor else it will call super() which is the call for the constructor of super class, now again from the super class constructor it will call the super class constructor if available. This is continued until it reaches the top of the class hierarchy. ---- Basically, a constructor is a block of code that gets executed each time a particular instance of a class is created. So, say you've designed a class for working with a database of some sort. When you create an instance of that class, copies of all the variables and functions of that class get attached to the instance-object, and if one of the functions is a constructor function, it will be run as soon as the instance-object is created. This lets you automatically set up conditions for the instance (i.e. establishing connections to different databases or reading data from different tables, or etc.). Depending on the language you're using, classes may or may not automatically call the constructor function of a parent or super class (if such exists, and if you do not provide a constructor for the class in question).
1 Explain the concepts of constructor and destructor Do you have to declare a constructor every time you create a class?
You only need a constructor if the default constructor will not suffice. Often times, it is useful to have a constructor that takes common parameters so that you do not have to write additional code. For example, a Point class might have a constructor for Point(int x, int y), which would be a shortcut for assigning x and y independently. Other classes may not need any default values assigned, and for this, it is acceptable to just use the default constructor. Finally, some classes are virtual, static, or abstract, and so may not need a constructor because the constructor is unnecessary (static), or may be defined elsewhere (virtual, abstract).
What are the numbers formulas and functions used in calculations called?
You can refer to them generally as values. Formulas can use operands and functions use arguments.You can refer to them generally as values. Formulas can use operands and functions use arguments.You can refer to them generally as values. Formulas can use operands and functions use arguments.You can refer to them generally as values. Formulas can use operands and functions use arguments.You can refer to them generally as values. Formulas can use operands and functions use arguments.You can refer to them generally as values. Formulas can use operands and functions use arguments.You can refer to them generally as values. Formulas can use operands and functions use arguments.You can refer to them generally as values. Formulas can use operands and functions use arguments.You can refer to them generally as values. Formulas can use operands and functions use arguments.You can refer to them generally as values. Formulas can use operands and functions use arguments.You can refer to them generally as values. Formulas can use operands and functions use arguments.
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.
In what order are the class constructors called when a derived class object is created?
We know that constructors are invoked at runtime when you say new on some class type as follows: Lamborghini h = new Lamborghini(); But what really happens when you say new Lamborghini() ? (Assume Lamborghini extends Car and Car extends Object.) 1. Lamborghini constructor is invoked. Every constructor invokes the constructor of its superclass with an (implicit) call to super(), 2. Car constructor is invoked (Car is the superclass of Lamborghini). 3. Object constructor is invoked (Object is the ultimate superclass of all classes, so class Car extends Object even though you don't actually type "extends Object" into the Car class declaration. It's implicit.) At this point we're on the top of the hierarchy. 4. Object instance variables are given their explicit values. By explicit values, we mean values that are assigned at the time the variables are declared, like "int x = 27", where "27" is the explicit value (as opposed to the default value) of the instance variable. 5. Object constructor completes. 6. Car instance variables are given their explicit values (if any). 7. Car constructor completes. 8. Lamborghini instance variables are given their explicit values (if any). 9. Lamborghini constructor completes.
