$68
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.
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.
An empty constructor takes no arguments and calls the default constructor
An implicit constructor call will always call the default constructor, whereas explicit constructor calls allow to chose the best constructor and passing of arguments into the constructor.
$68
$68
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.
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.
An empty constructor takes no arguments and calls the default constructor
Not much
An implicit constructor call will always call the default constructor, whereas explicit constructor calls allow to chose the best constructor and passing of arguments into the constructor.
You cannot pass an array to a copy constructor. A copy constructor only accepts a constant reference to the object being copied, which must be of the same class as the object being constructed. An array is not an object of any class, and therefore cannot be used in any copy constructor. Although you cannot pass an array to a copy constructor, you can pass an array to a non-trivial constructor. It is not recommended, however, as there's no way to bounds-check the array being passed, which could result in an invalid object being created -- which is never a good thing. Even if you pass the array and its dimension(s) to the constructor, how can you guarantee those dimensions are valid for the array being passed? And what will you do if they are invalid? After all, you cannot veto the construction of an object once you've called its class constructor. Not knowing why you want to pass an array to a copy constructor, or how you intend to initialise the members via an array, makes it somewhat difficult to determine the best solution for you. However, I would consider using mutators instead of constructors. There's still the problem with bounds-checking but at least you won't have to deal with it during the object's construction.
default constructor is used only when the programmer does not use a constructor to initialize objects. Once the programmer defines a constructor then the default constructor is no longer used
yes we can call constructor
Constructor is used to do something (written in constructor) immediately after object creation.
There is no such thing as a default parameterized constructor. The default constructor is always the 'no-arg' constructor and does not take any parameters or arguments as input