Are constructors necessary in Java?
Java doesn’t require a constructor when we create a class. … The compiler automatically provides a public no-argument constructor for any class without constructors. This is called the default constructor. If we do explicitly declare a constructor of any form, then this automatic insertion by the compiler won’t occur.
Is it necessary to have constructor?
4 Answers. You don’t need to code a constructor in a class. The system will generate a default constructor for you automatically if you don’t have any constructor.
Do all Java classes need constructors?
All classes have constructors by default: if you do not create a class constructor yourself, Java creates one for you. However, then you are not able to set initial values for object attributes.
What happens if we don’t use constructor in Java?
Answer: Java does not actually require an explicit constructor in the class description. If you do not include a constructor, the Java compiler will create a default constructor in the byte code with an empty argument.
Can constructor be private?
Yes. Class can have private constructor. Even abstract class can have private constructor. By making constructor private, we prevent the class from being instantiated as well as subclassing of that class.
Can we make constructor final?
No, a constructor can’t be made final. A final method cannot be overridden by any subclasses. As mentioned previously, the final modifier prevents a method from being modified in a subclass. … In other words, constructors cannot be inherited in Java therefore, there is no need to write final before constructors.
What is the benefit of using constructor?
Benefits of Constructor Overloading in Java
The class instances can be initialized in several ways with the use of constructor overloading. It facilitates the process of defining multiple constructors in a class with unique signatures. Each overloaded constructor performs various tasks for specified purposes.
Does constructor return a value?
There are no “return value” statements in the constructor, but the constructor returns the current class instance. We can write ‘return’ inside a constructor. … JustLike methods, we can overload constructors for creating objects in different ways.
Can a class run without constructor?
It is possible for a class to have no constructor. (An important distinction to draw here is that the JVM does not require all class files to have a constructor; however, any class defined in Java does have a default constructor if a constructor is not explicitly declared.
What do you call a constructor that accepts no arguments?
A constructor that takes no parameters is called a parameterless constructor. Parameterless constructors are invoked whenever an object is instantiated by using the new operator and no arguments are provided to new .
Is overriding possible in Java?
In Java, methods are virtual by default. We can have multilevel method-overriding. Overriding vs Overloading : … Overriding is about same method, same signature but different classes connected through inheritance.
What happens if no constructor?
Answer: If you do not include a constructor, the Java compiler will create a default constructor in the byte code with an empty argument. …
Can constructor be overloaded?
Yes! Java supports constructor overloading. In constructor loading, we create multiple constructors with the same name but with different parameters types or with different no of parameters.