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ION Group Interview Questions and Answers for Technical Profiles

Last Updated : 20 Oct, 2023
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ION Group is a global technology leader, providing innovative solutions for digital transformation and delivering cutting-edge services for businesses optimizing their online operations. ION Group offers a variety of technical roles in areas such as software engineering, data science, and IT infrastructure.

ION Group interviews for technical profiles can be challenging, but with the right preparation, you can increase your chances of success. This article provides a comprehensive list of common ION Group technical interview questions and answers. By reviewing this information, you can gain a better understanding of what to expect and be well-prepared to answer any questions that the interviewer may ask.

1. What is Object-Oriented Programming (OOP)?
As the name suggests uses objects in programming. Object-oriented programming aims to implement real-world entities like inheritance, hiding, polymorphism, etc. in programming.

2. Difference between comparing String using == and .equals() method in Java

Both the equals() method and the == operator are used to compare two objects in Java. == is an operator and equals() is method. But the == operator compares the reference or memory location of objects in a heap, whether they point to the same location or not.

3. What are Java Exceptions?
In Java, an Exception is an unwanted or unexpected event, that occurs during the execution of a program, i.e. at run time, that disrupts the normal flow of the program’s instructions.

4. Difference Between Call by Value and Call by Reference

Call By Value

Call By Reference

While calling a function, we pass the values of variables to it. Such functions are known as “Call By Values”. While calling a function, instead of passing the values of variables, we pass the address of variables(location of variables) to the function known as “Call By References.
In this method, the value of each variable in the calling function is copied into corresponding dummy variables of the called function. In this method, the address of actual variables in the calling function is copied into the dummy variables of the called function.
With this method, the changes made to the dummy variables in the called function have no effect on the values of actual variables in the calling function. With this method, using addresses we would have access to the actual variables and hence we would be able to manipulate them.
In call-by-values, we cannot alter the values of actual variables through function calls. In call by reference, we can alter the values of variables through function calls.
Values of variables are passed by the Simple technique. Pointer variables are necessary to define to store the address values of variables.

5. String Constant Pool in Java
 Java String Pool is a place in heap memory where all the strings defined in the program are stored. A separate place in a stack is there where the variable storing the string is stored.

6. What are the differences between Java and C++?




Platform C++ is Platform Dependent Java is Platform Independent
Application C++ is mainly used for System Programming Java is Mainly used for Application Programming
Hardware C++ is nearer to hardware Java is not so interactive with hardware
Global Scope C++ supports global and namespace scope. Java doesn’t support global scope.
Not Supporting

Functionality supported in Java but not in C++ are:

  • thread support
  • documentation comment
  • unsigned right shift(>>>)

Functionality supported in C++ but not in Java are:

  • goto
  • Pointers
  • Call by reference
  • Structures and Unions
  • Multiple Inheritance
  • Virtual Functions

7. Virtual Function in C++
A virtual function (also known as virtual methods) is a member function that is declared within a base class and is re-defined (overridden) by a derived class. 

8. Destructors in C++
Destructor is an instance member function that is invoked automatically whenever an object is going to be destroyed. Meaning, a destructor is the last function that is going to be called before an object is destroyed.

9. Find the Second largest element in an array
The approach is to traverse the array twice. In the first traversal find the maximum element.  In the second traversal find the greatest element in the remaining excluding the previous greatest.

10. Check whether two Strings are anagrams of each other
An anagram of a string is another string that contains the same characters, only the order of characters can be different. For example, “abcd” and “dabc” are an anagram of each other.

11. What are super, primary, candidate, and foreign keys?

  • A super key is a set of attributes of a relation schema upon which all attributes of the schema are functionally dependent. No two rows can have the same value of super key attributes.
  • A Candidate key is a minimal superkey, i.e., no proper subset of Candidate key attributes can be a superkey.
  • A Primary Key is one of the candidate keys. One of the candidate keys is selected as most important and becomes the primary key. There cannot be more than one primary key in a table..
  • A Foreign key is a field (or collection of fields) in one table that uniquely identifies a row of another table.

12. Normalization Process in DBMS

Database Normalization is a stepwise formal process that allows us to decompose database tables in such a way that both data dependency and update anomalies are minimized. It makes use of functional dependency that exists in the table and the primary key or candidate key in analyzing the tables. Normal forms were initially proposed called

13. What are the differences between DDL, DML, and DCL in SQL? 
Following are some details of three :

  • DDL stands for Data Definition Language. SQL queries like CREATE, ALTER, DROP, TRUNCATE and RENAME come under this. 
  • DML stands for Data Manipulation Language. SQL queries like SELECT, INSERT, DELETE and UPDATE come under this. 
  • DCL stands for Data Control Language. SQL queries like GRANT and REVOKE come under this. 

14. What are the differences between SQL and PL/SQL?



SQL is a query execution or commanding language PL/SQL is a complete programming language
SQL is a data-oriented language. PL/SQL is a procedural language
SQL is very declarative in nature. PL/SQL has a procedural nature.
It is used for manipulating data. It is used for creating applications.
We can execute one statement at a time in SQL We can execute blocks of statements in PL/SQL
SQL tells databases, what to do? PL/SQL tells databases how to do.
We can embed SQL in PL/SQL We can not embed PL/SQL in SQL

15. What is Denormalization?
Denormalization is a database optimization technique in which we add redundant data to one or more tables. This can help us avoid costly joins in a relational database. Note that denormalization does not mean not doing normalization. It is an optimization technique that is applied after normalization.

16. What is the difference between DELETE and TRUNCATE commands?



The DELETE statement removes rows one at a time and records an entry in the transaction log for each deleted row. TRUNCATE TABLE removes the data by deallocating the data pages used to store the table data and records only the page deallocations in the transaction log.
DELETE command is slower than the identityTRUNCATE command. While the TRUNCATE command is faster than the DELETE command.
To use Delete you need DELETE permission on the table. To use Truncate on a table we need at least ALTER permission on the table.
The identity of the column retains the identity after using DELETE Statement on the table. The identity of the column is reset to its seed value if the table contains an identity column.
The delete can be used with indexed views. Truncate cannot be used with indexed views.

17. ER Diagram of a Company
ER Diagram is known as Entity-Relationship Diagram, it is used to analyze to structure of the Database. It shows relationships between entities and their attributes. An ER Model provides a means of communication.

18. What are ACID Properties?
A transaction is a single logical unit of work that accesses and possibly modifies the contents of a database. Transactions access data using read and write operations. 

19. Degree of Relations in DBMS
In DBMS, a degree of relationship represents the number of entity types that associate in a relationship. For example, we have two entities, one is a student and the other is a bag and they are connected with the primary key and foreign key. So, here we can see that the degree of relationship is 2 as 2 entities are associating in a relationship.

20. Difference between Where and Having Clause in SQL

WHERE Clause


WHERE Clause is used to filter the records from the table based on the specified condition. HAVING Clause is used to filter record from the groups based on the specified condition.
WHERE Clause can be used without GROUP BY Clause HAVING Clause cannot be used without GROUP BY Clause
WHERE Clause implements in row operations HAVING Clause implements in column operation
WHERE Clause cannot contain aggregate function HAVING Clause can contain aggregate function
WHERE Clause can be used with SELECT, UPDATE, DELETE statement. HAVING Clause can only be used with SELECT statement.

21. What is a Thread?  
A thread is a single sequence stream within a process. Because threads have some of the properties of processes, they are sometimes called lightweight processes.

22. Difference between Process and Thread



Process means any program is in execution. Thread means a segment of a process.
The process takes more time to terminate. The thread takes less time to terminate.
It takes more time for creation. It takes less time for creation.
It also takes more time for context switching. It takes less time for context switching.
The process is less efficient in terms of communication. Thread is more efficient in terms of communication.

23. Techniques to handle Thrashing
Thrashing is a condition or a situation when the system is spending a major portion of its time servicing the page faults, but the actual processing done is very negligible. 

24. What is a kernel?
A kernel is the central component of an operating system that manages the operations of computers and hardware. It basically manages operations of memory and CPU time.

25. What is the Caching Mechanism?
It is the process of storing and accessing data from memory(i.e. cache memory). The main feature of caching is to reduce the time to access specific data. 

26. What is the difference between the Operating system and kernel?

Operating System


Operating System is system software. The kernel is system software that is part of the Microkerneloperating system.
Operating System provides an interface b/w the user and the hardware. The kernel provides an interface b/w the application and hardware.
It also provides protection and security. Its main purpose is memory management, disk management, process management and task management.
All system needs a real-time operating real-time, and Microkernel system to run. All operating system needs a kernel to run.
Type of operating system includes single and multiuser OS, multiprocessor OS, real-time OS, Distributed OS. Type of kernel includes Monolithic and Microkernel.
It is the first program to load when the computer boots up. It is the first program to load when the operating system loads

27. What is a deadlock?  
A deadlock is a situation where a set of processes are blocked because each process is holding a resource and waiting for another resource acquired by some other process. 

28. Write a difference between paging and segmentation.



In paging, program is divided into fixed or mounted-size pages. In segmentation, the program is divided into variable-size sections.
For the paging operating system is accountable. For segmentation compiler is accountable.
Page size is determined by hardware. Here, the section size is given by the user.
It is faster in comparison of segmentation. Segmentation is slow.
Paging could result in internal fragmentation. Segmentation could result in external fragmentation.

29. Name of the software layers or User support layer in the OSI model.

30. What is VPN? How It Works

VPN stands for the Virtual Private Network. A virtual private network (VPN) is a technology that creates a safe and encrypted connection over a less secure network, such as the Internet.

31. What is IP Spoofing?
IP Spoofing is essentially a technique used by hackers to gain unauthorized access to Computers. Concepts of IP Spoofing were initially discussed in academic circles as early as 1980. IP Spoofing types of attacks had been known to Security experts on the theoretical level.

32. Advantages and Disadvantages of Fibre optic Cable
The advantages of Fiber Optics are mentioned below:

  • Bandwidth is above copper cables.
  • Less power loss and allows data transmission for extended distances.
  • The optical cable is resistant to electromagnetic interference.
  • Fiber cable is sized 4.5 times which is best than copper wires.
  • As the cable is lighter, and thinner, in order that they use less area as compared to copper wires.
  • Installation is extremely easy thanks to less weight.

33.What is the difference between Bluetooth and wifi? 

Bluetooth Wifi
Bluetooth has no full form. While Wifi stands for Wireless Fidelity.
It requires a Bluetooth adapter on all devices for connectivity. Whereas it requires a wireless adapter Bluetooth for all devices and a wireless router for connectivity.
Bluetooth consumes low power. while it consumes high power.
The security of BlueTooth is less in comparison to the number of wifi. While it provides better security than BlueTooth.
Bluetooth is less flexible means these limited users are supported. Whereas wifi supports a large number of users.

34.What are Firewalls?
A firewall is a network security device, either hardware or software-based, which monitors all incoming and outgoing traffic and based on a defined set of security rules it accepts, rejects or drops that specific traffic

35. Explain TCP model
TCP/IP was designed and developed by the Department of Defense (DoD) in the 1960s and is based on standard protocols. It stands for Transmission Control Protocol/Internet Protocol. The TCP/IP model is a concise version of the OSI model. It contains four layers, unlike the seven layers in the OSI model.

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