JAVA is one of the most familiar languages to create websites and platforms. As discussed earlier here we have given the most frequently asked JAVA interview questions: Section 2. This helps candidates to overcome their fear of JAVA Training.
Can we override or overload static methods in JAVA?
Overloading: Overloading is related to compile time polymorphism. This allows having different signatures with various methods of the same name, especially type and the number of input parameters.
Can we overload static methods? ‘Yes’. Static methods can be overloaded with two or more methods with same name but different input parameters.
Overriding: This is related to run-time polymorphism.
Can we override static methods in java? As they contain a run-time polymorphism, we declare them with the same signature, so cannot override static methods in java. They are looked up statically.
What is the scope of variables in Java in following cases?
Member Variables: These are declared outside the class but inside a class. They can be accessed anywhere in the class.
Loop Variables: A variable declared inside a pair of brackets has more value and scope in a method.
Local Variables: A method which is declared inside a method cannot be accessed outside. These are called as local variables.
What happens when you remove static modifier from the main method?
In this case, the program gets compiled but shows a runtime error “NoSuchMethodError”
“this” keyword in java
With an instance or constructor, this is a reference to the current object.
this keyword usage
It is for referring and invoking current class instance variable. It passes an argument in the method and constructor call.
What is an abstract class and why they are similar or different in Java from C++?
Abstract classes are classes which contain one or more methods. It contains no implementation. It may not be instantiated and require subclasses to deliver. Like C++, Java has an instance of an abstract class which cannot be created. They also have final methods which cannot be overridden. For example, the following program compiles and runs fine. Get to know more about in Java Course in Chennai.
Which class is the superclass of every class?
What is object cloning?
Object cloning is meant for creating the exact copy of the original object. If you need to support cloning in a class, it implementing java.lang is mandatory. If it doesn’t implement it throws an exception ‘CloneNotSupportedException’
Can we private methods be overridden in Java?
A private method can’t be overridden in Java because it not visible from any other class.
What is blank final variable?
In Java final variable can be assigned only once, we can assign a value later or in the declaration.
What is “super” keyword?
The super keyword is used to refer parent class objects. The keyword ‘super’ came into the picture along with the concept of Inheritance.
Scenarios of using java super Keyword:
“super” is used to refer immediate parent instance variable, call parent class method and immediate parent constructor.
The word static is used for memory management. We can apply these with methods, blocks, variables and nested class.
How are Java objects stored in memory?
All objects are dynamic in Java. This differs from C++ where objects are allocated objects on Stack on Heap. To allocate memory to an object, we must use new(). So the object is always allocated memory on the heap.
Get to know more about the most frequently asked Java interview questions in our next session. Enroll for Java Training in Chennai with FITA!!