# HCLTech Interview Questions with Answers

8 previously-asked interview questions from HCLTech's hiring process, each with the correct answer and a worked explanation. Written against the company's actual test pattern.

_Source: Astra (https://useastra.in). Updated 2026-09-05._

### 1. What is the difference between a while loop and a do-while loop?

**Answer:** A while loop checks its condition before executing the body, so it may run zero times. A do-while loop executes the body once first and then checks the condition, so it always runs at least once.

**Explanation:** while checks first; do-while runs at least once.

### 2. What is inheritance in object oriented programming?

**Answer:** Inheritance lets a child class reuse and extend the attributes and methods of a parent class, modelling an is-a relationship. It promotes code reuse and supports polymorphism. Types include single, multilevel, and hierarchical inheritance.

**Explanation:** Child class reuses and extends a parent; an is-a relationship.

### 3. What is a primary key in a database?

**Answer:** A primary key is a column or set of columns that uniquely identifies each row in a table. It cannot contain null values and must be unique. Each table can have only one primary key.

**Explanation:** Uniquely identifies rows; unique and not null.

### 4. What is the difference between the GET and POST HTTP methods?

**Answer:** GET requests data and appends parameters to the URL, so it is visible, cacheable, and limited in size. POST sends data in the request body, is not shown in the URL, supports larger payloads, and is used to create or change data.

**Explanation:** GET sends data in the URL; POST sends it in the body.

### 5. What is a linked list and what advantages does it have over an array?

**Answer:** A linked list is a sequence of nodes where each holds data and a pointer to the next. Compared with arrays it offers dynamic size and O(1) insertion or deletion at a known position, though it loses O(1) random access and uses extra memory for pointers.

**Explanation:** Nodes with pointers; dynamic size and cheap insert or delete.

### 6. What is DNS and what does it do?

**Answer:** The Domain Name System translates human readable domain names such as example.com into the numeric IP addresses that computers use to route traffic. It works like the phone book of the internet.

**Explanation:** Translates domain names to IP addresses.

### 7. Tell me about yourself.

**Answer:** Give a concise 60 to 90 second overview: your degree, key skills, a project or internship with its impact, and why HCLTech interests you. Keep it structured and relevant.

**Explanation:** Structured pitch: background, skills, project, fit.

### 8. Why do you want to join HCLTech?

**Answer:** Mention HCLTech global presence, its wide range of technology services and products, strong fresher training, and growth opportunities. Tie it to your goal of gaining broad experience early in your career.

**Explanation:** Global scale, variety of work, training, growth.

More HCLTech preparation, including the full recruitment process: https://useastra.in/campus/hcl