Every class, including abstract classes, MUST have a constructor. Hard Code that into your brain. But just because a class must have one, doesn't mean the programmer has to type it. A constructor looks like this:
class Car {
Car() { } // The constructor for the Car class
}
You notice anything missing in the declaration above? There's no return type! Two key points to remember about constructors are that they have no return type and their names must exactly match the class name. Typically, constructors are used to initialize instance variable state, as follows:
class Car {
int size;
String name;
Car(String name, int size) {
this.name = name;
this.size = size;
}
}
The two types of constructors are: default or no-arg constructor and constructor with args.
Every class, including abstract classes, MUST have a constructor. The different types are: a. Regular constructors b. Overloaded constructors and c. Private constructors
Yes. At least in Java, that's possible, as long as the constructors have a different number, or different types of, parameters.
No. Java does not support copy constructor
Yes, you can have more than one constructor with a different set of parameters.
Java has 2 types of constructors based on parameters passed:Default or parameter-less constructor: A constructor which does not accept any arguments.Parametrized constructor: A constructor which accepts one or more arguments.Similarly based on Access modifier also we have:Public constructor - Class can be instantiated by anyonePrivate constructor - Class cannot be instantiated by anyoneProtected constructor - Class can be instantiated only by sub classes
When any constructor is deffined in your class, the java compiler create a default no argument constructor for you. This constructor only have an invocation to the super class constructor (" super( ) ").
All Java programs would have a constructor... public class Test { public Test(){ ... } ..... } This is a constructor. Even if you dont code the constructor Java would automatically place a default constructor for compilation.
Constructor is used to do something (written in constructor) immediately after object creation.
No. if you wish to create an object that you plan on using in a java program then the answer is NO. You cannot initialize an object of a Java class without calling the constructor.
No.
Java, unlike C++ does not support copy constructors.
NO, we cannot create a contructor for an interface in java.