Top 20 Infosys Technical Interview Questions and Answers(2023)

Infosys is a dream of many and cracking its interview is one of the most challenging yet exciting parts of the entire recruitment process. Here, the interviewers are pretty friendly with the candidates and ask many technical questions and some critical HR-related questions to analyze their knowledge. Infosys is not purely technical however, they aim to work on your overall personality and give the required boost. So, if you dream of joining an Indian IT MNC, Infosys might be on your list at the number one position.

To help you with the entire Interview preparation process, Board Infinity has curated the list of top Infosys interview questions and answers that can open the doors of success for you. This list has been compiled based on the past year's interview questions and the most asked questions. So, let’s get started!

1. What are some advanced-level programming languages.

The most popular programming languages are C, Java, C++, Swift, JavaScript, Go, and PHP. (You can also mention the languages you’ve got in-depth knowledge of among these. If you’re prepared with all of them, you would definitely fetch brownie points here.

2. Is C a low-level programming language? If not, then why is it considered so at times?

C continuously supports the high-level programming language actions and is also machine-independent, which is a feature of a high-level language, however, at times it comes under the category of low-level programming languages as it allows direct memory access, raw pointers, and bit-oriented operation.

It has no automatic memory management which confirms its low level. Depending on its comparison with other languages, it can be classified sometimes as high level, if compared to ‘Assembly’, but low level if compared to JavaScript. It is subjective and therefore would be better classified as a mid-level language.

3. Mention the preprocessor of C.

The preprocessor does not come as a part of the compiler. However, it is a separate step during compilation. Commands mentioned at the top of the program code, which starts with the symbol ‘#’ are called the preprocessor of C. In layman language, it is a tool that is used to substitute text, which dictates the compiler to pre-process before the final compilation.

4. What are the basic OOPs concepts?

The basic OOPs concepts include Encapsulation, Polymorphism, Inheritance, and Abstraction.

Inheritance is the process by which one class assumes or inherits the characteristics, methods, and properties of another class. Along with the inherited characteristics also exist new and different characteristics.

Encapsulation is, in essence, the concept of security. It helps in hiding the data from unauthorized users.

Polymorphism refers to the concept of giving the functions different functionalities but the same name.

Abstraction is a concept that hides the executions of the functions and only showcases the functionalities.

5. Explain Inheritance.

Inheritance can be described as one of the most important components of the language OOPs. It is the process by which one class assumes or inherits the characteristics, methods, and properties of another class, which basically allows you to reuse a code instead of writing it anew.

6. Please list the different types of inheritance.

There are six types of inheritance.

• Single Inheritance
• Multiple Inheritance
• Multi-level Inheritance
• Hierarchical Inheritance
• Hybrid Inheritance

7. Mention the tokens in C++

In C++, tokens are the tiniest elements that together make much more sense to the compiler. Literals, operators, Identifiers, keywords, separators, and punctuations are common examples of tokens.

8. Give some differences between Java and C++

9. Give some differences between C and C++ Give some differences between C and C++

10. What are the examples of data structures in C++?

When talking about C++, there are two different types of data structures in C++ namely linear and non-linear

• In linear C++, the data elements are placed in a sequence. Examples of it are linked list, queue, and stack.
• In non-linear C++ the graph and tree are not placed sequentially.

11. Give one disadvantage of using C++

In C++, there is no support for the threads. This is a major disadvantage as this function exists in other languages. The absence of this not only makes the process extremely slow but also makes it extra complicated.

12. Explain the SQL join?

The join is used for getting results from several tables using the foreign and primary keys of the related tables and combining the rows of the tables. For example -

For getting the book name that the student has taken, the query can be simply written as -

select student.student_batch,  student.student_name, a book where student.student_id = book.student_id,  book.book_title, book.book_author from student:

The result will appear as  -

13. Tell us the full form of HTML.

HTML stands for Hypertext Mark-up Language.

14. List three differences each between heap and stack memory.

15. Explain how the polymorphism is implemented in Java?

There are two ways for the polymorphism implementation in Java. These include dynamic polymorphism or Method overloading.

Here is the example of Method overloading -

The output of these two code sources will be “Welcome to IndianPizza, fresh dough is ready!”

16. Give us in writing a program to state that the given number is a prime number.

Let’s imagine that the given number is 47.

17. Give us a difference between ArrayList and Array

Here are the differences between ArrayList and Array -

• The ArrayList can grow immensely. However, the Array has only a fixed length.
• On the one hand, the ArrayList cannot store any primitives. On the other hand, it's the opposite with the Array as it can easily store primitives.

18. Give us some differences between Windows and DOS

19. Give some differences between the varchar and char in DBMS

20. Name three types of loops in Java.

The three types of loops in Java can be the While loop, For loop, and finally, Do While loop.

For loop is an entry-controlled loop. It allows a user to carry out a block of a statement(s) repeatedly with a static number of tries on the basis of the expression of the test or the conditions of the test.

While loop is also an entry-controlled loop. It repeats while the condition of the test and the expression of the tests estimate to be true.

Do-while loop, differing from the while loop and the for loop, is an exit-controlled loop. It evaluates its expression or the condition of the test after executing the statements in the loop-body, at the bottom of the loop.

Conclusion

Today, we listed some of the most frequently asked questions while appearing for the Infosys Interview. Over the years, it has been recorded that most of the questions have been asked from C and C++ along with OOPs concept, the basis of programming languages, and other technical stuff that every developer should know.

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