Can a constructor return null?

Thanks In Advance !! We can not return any value from constructor... A constructor does not return anything; the "new" operator returns an object that has been initialized using a constructor. If you really want a constructor that may return null, perhaps you should check out the factory method pattern.

Can new Java return null?

Java Constructors Never Return Null.

Can constructors have a return?

No, constructor does not have any return type in Java. Constructor looks like method but it is not. It does not have a return type and its name is same as the class name. Mostly it is used to instantiate the instance variables of a class.

Does a constructor have a return type of void?

A constructor does not have a return type, so as you wrote void in front of A(), you've defined a method, not a constructor.

Can a constructor return false?

No. Constructors do not have return values.

Can a constructor return a NULL value - C++

Can constructor be static?

No, we cannot define a static constructor in Java, If we are trying to define a constructor with the static keyword a compile-time error will occur. In general, static means class level. A constructor will be used to assign initial values for the instance variables.

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. The main intention of making a method final would be that the content of the method should not be changed by any outsider.

What happens if constructor has a return type?

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

Can a constructor be private?

Yes, we can declare a constructor as private. If we declare a constructor as private we are not able to create an object of a class. We can use this private constructor in the Singleton Design Pattern.

Can a constructor be overloaded?

Constructors can be overloaded in a similar way as function overloading. Overloaded constructors have the same name (name of the class) but the different number of arguments. Depending upon the number and type of arguments passed, the corresponding constructor is called.

Can constructor return a value in C++?

You do not specify a return type for a constructor. A return statement in the body of a constructor cannot have a return value.

Is null constructor?

If a constructor does not take any data arguments, it is nullary.

Can we return null in catch block?

Is returning null in catch block is best practice.. Best is a relative word. If you want to swallow / disregard the exception then you would return null. i.e. you cannot do anything about the exception but still want to continue processing then this might be "best".

Can you print null?

It's just the string and the character array parameters that cause ambiguity as character arrays and objects can happily coexist. The char array null cannot be printed by the PrintStream since it causes a NullPointerException .

Can constructors be virtual?

In C++, the constructor cannot be virtual, because when a constructor of a class is executed there is no virtual table in the memory, means no virtual pointer defined yet. So, the constructor should always be non-virtual. But virtual destructor is possible.

Can a constructor be overridden?

Constructor looks like method but it is not. It does not have a return type and its name is same as the class name. But, a constructor cannot be overridden. If you try to write a super class's constructor in the sub class compiler treats it as a method and expects a return type and generates a compile time error.

Can we create immutable class in Java?

Immutable class in java means that once an object is created, we cannot change its content. In Java, all the wrapper classes (like Integer, Boolean, Byte, Short) and String class is immutable. We can create our own immutable class as well.

Can abstract methods have constructor?

Like any other classes in Java, abstract classes can have constructors even when they are only called from their concrete subclasses.

Can you use this () and super () both in a constructor?

If we include “this()” or “super()” inside the constructor, it must be the first statement inside it. “this()” and “super()” cannot be used inside the same constructor, as both cannot be executed at once (both cannot be the first statement). “this” can be passed as an argument in the method and constructor calls.

Can we create object of abstract class?

We cannot create objects of an abstract class. To implement features of an abstract class, we inherit subclasses from it and create objects of the subclass. A subclass must override all abstract methods of an abstract class.

Can static method be overridden?

Static methods are bonded at compile time using static binding. Therefore, we cannot override static methods in Java.

Can a main () method be declared final?

Yes, we can declare the main () method as final in Java. The compiler does not throw any error. If we declare any method as final by placing the final keyword then that method becomes the final method.

Can we overload main method?

Yes, we can overload the main method in Java, but When we execute the class JVM starts execution with public static void main(String[] args) method.

Can we inherit constructor in Java?

Constructors are not members, so they are not inherited by subclasses, but the constructor of the superclass can be invoked from the subclass.

Can you declare an abstract class as final?

If you declare a class abstract, to use it, you must extend it and if you declare a class final you cannot extend it, since both contradict with each other you cannot declare a class both abstract and final if you do so a compile time error will be generated.