10+ Dr. Reddy's Interview Questions and Answers

Abstract class can have both abstract and non-abstract methods, while interface can only have abstract methods.

• Abstract class can have constructors, member variables, and methods with implementation.

• Interface can only have abstract methods and constants.

• A class can implement multiple interfaces but can only extend one abstract class.

• Example: abstract class Animal { abstract void sound(); void eat() { // implementation } }

• Example: interface Shape { void draw(); }

Yes, static methods can be used in interfaces in Java.

• Static methods in interfaces were introduced in Java 8.

• Static methods can be called using the interface name.

• Static methods in interfaces are used for providing utility methods.

• Example: interface MyInterface { static void myMethod() { System.out.println("Static method in interface"); }}

Polymorphism in Java can be achieved through method overloading and method overriding.

• Method overloading: Having multiple methods in the same class with the same name but different parameters.

• Method overriding: Subclass provides a specific implementation of a method that is already provided by its superclass.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• Example: Animal class with a method 'makeSound', and subclasses Dog and C...read more

Exception handling in Java is a mechanism to handle runtime errors and prevent program termination.

• Java provides try, catch, and finally blocks to handle exceptions.

• Checked exceptions must be caught or declared in the method signature.

• Unchecked exceptions do not need to be caught or declared.

• Example: try { // code that may throw exception } catch (Exception e) { // handle exception }

• Example: try { // code that may throw exception } finally { // cleanup code }

Reverse a string using popular programming languages

• Use built-in functions like reverse() in Python

• Iterate through the string in reverse order in C++

• Use StringBuilder.reverse() in Java

Use the length() function to find the length of the given string.

• Use the length() function in programming languages like Java, Python, C++, etc.

• For example, in Java: String str = 'hello'; int length = str.length();

• Make sure to handle edge cases like empty strings or null values.

A prime number is a number greater than 1 that can only be divided by 1 and itself.

• Use a loop to check if the number is divisible by any number other than 1 and itself

• Start checking from 2 up to the square root of the number for efficiency

• If the number is only divisible by 1 and itself, it is a prime number

Use a set to remove duplicates from a string

• Create a set to store unique characters

• Iterate through the string and add each character to the set

• Convert the set back to a string to get the result

Replace characters from string with another character

• Use a loop to iterate through each character in the string

• Check if the character needs to be replaced and replace it with the desired character

• Return the modified string