The first thing to note about constructor overloading is that Java creates a no argument constructor for you if and only if you have not typed a constructor yourself. Every class has a constructor even abstract ones (default no argument constructor). Abstract constructors are always executed.
To overload a constructor you can do the following:
class Test {
String name;
Test(String n) {
name = n;
System.out.println("Constructing Test Object named: " + name);
}
}
In the case above we are overloading the default no argument constructor with a constructor that takes a String parameter.
You can write you own no argument constructor as follows:
class Test {
Test() {
System.out.println("Constructing Test Object");
}
}
To override our own no argument constructor we do this:
class Test {
Test() { // our no argument constructor
System.out.println("Constructing Test Object");
}
String name;
Test(String n) { // overloading our no argument constructor with this
// constructor that take a String parameter
name = n;
System.out.println("Constructing Test Object named: " + name);
}
}
really there is no difference between constructor overloading and metho overloading
yes,because in constructor overloading constructor have same and different parameter list. In method overloading method have same name and different parameter list.
There is no difference between them.
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.
I think constructor overloading is the concept of polymorphism.
When we are initializing our object with different internal state then we can use the constructor overloading.
Overloading constructor means when you have multiple constructors in a class but with different number of arguments. We cannot override a constructor, but we can override a method having same arguments and same return type. This means when I subclass a particular class then I can call the superclass's class method and override that with subclass's own logic.
Constructor overloading, just like any function's overloading, is where more than one configuration of parameters exists for the function. Based on the number and type of the parameters, different versions of the function can be resolved by the linker. This is typically used in the constructor as the default constructor (no parameters), the copy constructor (one reference parameter of the same type as the class), and the conversion constructor (any other combination of parameters).
Yes. Method Overloading is a form of Polymorphism
method overloading means function having same name but different prototype .. e.g class demo { int i; public void display() { System.out.println("hello"); } public void display(int x) //method overloading { i=x; System.out.println("i="+i); } } class mainDemo { public static void main(String s[]) { demo ob=new demo();//creating object ob.display(); ob.display(5); } }
A copy constructor usually refers to a constructor which takes an object, and returns a copy of that object. I can think of no way to overload the constructor without changing its functionality.
Overloading a constructor means typing in multiple versions of the constructor, each having a different argument list, like the following examples: class Car { Car() { } Car(String s) { } } The preceding Car class has two overloaded constructors, one that takes a string, and one with no arguments.