Which is a no-arg constructor inserted by the compiler?

Which is a no-arg constructor inserted by the compiler?

The default constructor is inserted by compiler and has no code in it, on the other hand we can implement no-arg constructor in our class which looks like default constructor but we can provide any initialization code in it.

What is the first line of a constructor in Java?

The first line of a constructor must either be a call on another constructor in the same class (using this ), or a call on the superclass constructor (using super ). If the first line is neither of these, the compiler automatically inserts a call to the parameterless super class constructor.

How do you call the no-arg constructor from the constructor which has an argument?

In that case you have to explicitly define a no-argument constructor (which is not default by the way, because it’s not provided by the compiler), e.g. public MyClass() { } . And you can call it from other constructor as this(); , which must be the first statement in the constructor where it’s being called.

What should be the first line in a constructor?

Actually, super() is the first statement of a constructor because to make sure its superclass is fully-formed before the subclass being constructed. Even if you don’t have super() in your first statement, the compiler will add it for you!

What is the first line that is called in a derived class constructor?

base class constructor call
The point to note is base class constructor call must be the first line in derived class constructor.

What is the by default first statement in constructor?

Actually, super() is the first statement of a constructor because to make sure its superclass is fully-formed before the subclass being constructed.

Does order matter in constructor chaining?

Hence, order in constructor chaining is not important. Constructor Chaining to other class using super() keyword : Java.

Which of the following statement about constructor is not true?

What is false about constructor? Explanation: The constructor cannot have a return type. It should create and return new objects. Hence it would give a compilation error.

How do you make a no arg constructor?

Generating private no-args/default constructor To generate private no-args constructor declare @NoArgsConstructor(access = AccessLevel. PRIVATE) . access attribute of @NoArgsConstructor allows you to change the access modifier of the generated constructor.

How can a Java class have no no-arg constructor?

How can a Java class have no no-arg constructor? All classes have at least one constructor. If a class does not explicitly declare any, the Java compiler automatically provides a no-argument constructor, called the default constructor.

What is default constructor with no arguments?

No-argument constructor: A constructor that has no parameter is known as the default constructor. If we don’t define a constructor in a class, then the compiler creates default constructor (with no arguments) for the class. And if we write a constructor with arguments or no-arguments then the compiler does not create a default constructor.

What happens if we don’t define a constructor in a class?

If we don’t define a constructor in a class, then compiler creates default constructor (with no arguments) for the class. And if we write a constructor with arguments or no-arguments then the compiler does not create a default constructor. Default constructor provides the default values to the object like 0, null, etc. depending on the type.

What is the default constructor of a Java class?

If a class does not explicitly declare any, the Java compiler automatically provides a no-argument constructor, called the default constructor. This default constructor calls the class parent’s no-argument constructor, or the Object constructor if the class has no other parent.