Grappus Java Developer Interview Questions and Answers

I am a software developer with a passion for coding and problem-solving. My family is supportive and has always encouraged my career in tech.

• Experienced software developer

• Passionate about coding and problem-solving

• Supportive family that encourages my career in tech

Autoboxing is the automatic conversion of primitive data types to their corresponding object wrapper classes.

• Autoboxing is useful when working with collections that require objects instead of primitives.

• Example: int i = 5; Integer j = i; //autoboxing

• Unboxing is the opposite of autoboxing, where an object of a wrapper class is converted back to its corresponding primitive type.

• Example: Integer j = 5; int i = j; //unboxi

Typecasting up and down refers to converting a variable of one data type to another data type of higher or lower precision.

• Typecasting up involves converting a variable of lower precision to a variable of higher precision, such as converting an int to a double.

• Typecasting down involves converting a variable of higher precision to a variable of lower precision, such as converting a double to an int.

• Typecasting can resul...read more

To iterate a map in Java, use a for-each loop or an iterator.

• Use the entrySet() method to get a set of key-value pairs

• For-each loop: for(Map.Entry entry : map.entrySet())

• Iterator: Iterator> iterator = map.entrySet().iterator();

• Use hasNext() and next() methods to iterate through the map

Types of synchronization in Java

• Synchronized methods

• Synchronized statements

• ReentrantLock

• Semaphore

• CountDownLatch

Access modifiers in method overriding

• Access modifiers in the overriding method cannot be more restrictive than the overridden method

• The access modifier can be less restrictive or the same as the overridden method

• Private methods cannot be overridden

• Examples: public method can be overridden by public or protected method, but not by private method

I know multiple programming languages including Java, Python, and C++.

• Proficient in Java with experience in developing web applications using Spring framework

• Familiar with Python for data analysis and machine learning

• Experience in C++ for developing high-performance applications

• Also familiar with HTML, CSS, and JavaScript for front-end development

Class is a blueprint for creating objects, encapsulation is the process of hiding data and methods within a class.

• Class is a template or blueprint that defines the properties and behaviors of an object.

• Encapsulation is the process of bundling data and methods together within a class, hiding the internal details from the outside world.

• Other features of OOP include inheritance, polymorphism, and abstraction.

• Inheritance a...read more

Program to find the sum of squares of each term of Fibonacci series

• Generate Fibonacci series using loop or recursion

• Calculate square of each term

• Add all squares to get the sum

I would like to join Cognizant because of its reputation as a leading global technology and consulting company.

• Cognizant has a strong presence in the industry and is known for its innovative solutions.

• I am impressed by Cognizant's commitment to digital transformation and its ability to deliver value to clients.

• The company offers excellent career growth opportunities and a supportive work environment.

• Cognizant's diverse...read more

A C code that prints out the elements of an array of strings.

• Declare an array of strings

• Use a loop to iterate through the array

• Print out each element

The probability of rain in Chennai today depends on various factors such as season, weather conditions, and location.

• The probability can be estimated by analyzing the current weather patterns and historical data.

• Factors such as humidity, temperature, and wind speed can affect the probability of rain.

• Local weather forecasts and satellite imagery can also provide insights into the likelihood of rain.

• The probability of ra...read more

It is impossible to accurately predict the probability of India winning the next Cricket World Cup.

• Sports events are unpredictable and depend on various factors such as team performance, weather conditions, injuries, etc.

• Past performance of the team and individual players can be considered, but it does not guarantee future success.

• Other teams participating in the tournament also play a significant role in determining t...read more