80+ Sdet Engineer Interview Questions and Answers

I have worked on multiple projects involving Selenium API for automated testing of web applications.

• Developed test scripts using Selenium WebDriver to automate testing of web applications

• Utilized Selenium Grid for parallel testing across different browsers and platforms

• Integrated Selenium with testing frameworks like TestNG or JUnit for test execution and reporting

• Implemented Page Object Model design pattern for better test maintenance and readability

Yes, the internal data structure can be changed without affecting user interaction as long as public methods remain the same.

• Use abstraction to hide implementation details from users

• Ensure public methods have consistent behavior regardless of internal data structure

• Consider using interfaces or abstract classes to define common behavior

This task involves writing a login function to retrieve and print employee details like first name and salary.

• Define a function named 'printEmployeeDetails'.

• Use a data structure (like an array or list) to store employee information.

• Each employee can be represented as an object or dictionary with 'firstName' and 'salary' keys.

• Iterate through the employee list and print the 'firstName' and 'salary' for each employee.

• Example: For an employee object: { 'firstName': 'John', 'salar...read more

Determine the minimum steps to deplete fuel from two types of tanks in an array of fuel amounts.

• Choose Two Fuels: You can only use two types of fuels at each step, e.g., O2 and H2.

• Step Calculation: Each step reduces the amount of fuel in the chosen tanks by 1.

• Example: For [4, 5, 6], if you choose O2 and H2, you can deplete them in 5 steps.

• Strategy: Prioritize using the fuels with the highest amounts to minimize total steps.

Selenium program to automate adding items to cart on Swiggy

• Launch the Swiggy website using Selenium WebDriver

• Search for desired food items and add them to cart

• Verify items are added correctly before proceeding to checkout

I have designed reusable methods for data validation, logging, and error handling.

• Created a data validation method that checks for required fields and data types

• Implemented a logging method that records important events and errors

• Developed an error handling method that gracefully handles exceptions and provides detailed error messages

Explanation of OOPs concepts with a class implementation

• Encapsulation: Class with private data members and public methods to access them

• Inheritance: Class extending another class to inherit its properties and methods

• Polymorphism: Class with multiple methods with the same name but different parameters

• Abstraction: Class with abstract methods that must be implemented by subclasses

I have implemented RESTful APIs using Node.js and Express framework in my project.

• Implemented CRUD operations for managing user data

• Used authentication middleware for secure access

• Integrated third-party APIs for external data retrieval

The API for capturing audio files is MediaRecorder in Android. Gradle is a build automation tool for Android projects.

• MediaRecorder API is used for capturing audio files in Android

• Gradle is a build automation tool used for building, testing, and deploying Android projects

• Example: MediaRecorder recorder = new MediaRecorder();

• Example: Gradle file for an Android project is typically named build.gradle

To center a div horizontally and vertically, use CSS flexbox or grid layout

• Use CSS flexbox with 'justify-content: center' and 'align-items: center'

• Alternatively, use CSS grid with 'place-items: center'

• Set the div's width and height, and margin: auto to center horizontally

Encapsulation is the concept of bundling data and methods that operate on the data into a single unit, while abstraction is the concept of hiding the implementation details and showing only the necessary features of an object.

• Encapsulation is about wrapping the data (variables) and methods (functions) that operate on the data into a single unit (class).

• Abstraction is about hiding the implementation details and showing only the necessary features of an object.

• Encapsulation hel...read more

Code to check if a string meets password requirements using built-in Java functions.

• Use String class methods like length(), contains(), matches() to check for password requirements.

• Use regular expressions to validate password requirements such as minimum length, uppercase, lowercase, digits, special characters.

• Example: String password = "Pass123!"; boolean isValid = password.length() >= 8 && password.matches(".*[A-Z].*") && password.matches(".*[a-z].*") && password.matches("....read more

Severity, Priority, and Criticality are different aspects of issue management in software testing.

• Severity refers to the impact of a defect on the system's functionality.

• Priority indicates the order in which defects should be fixed based on business needs.

• Criticality combines severity and priority to determine the overall importance of a defect.

• For example, a defect causing a system crash would have high severity, high priority, and high criticality.

• On the other hand, a minor...read more

Popular HTTP status codes and their meanings

• 200 - OK: Request succeeded

• 404 - Not Found: Resource not found

• 500 - Internal Server Error: Server error

• 401 - Unauthorized: Authentication required

• 302 - Found: Resource temporarily moved

• 503 - Service Unavailable: Server unavailable

Different methods to reverse strings in an array

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

• Iterate through each string and reverse characters manually

• Use recursion to reverse each string

Identify bugs in a given program by analyzing its functionality and expected behavior.

• Check for syntax errors: e.g., missing semicolons or brackets.

• Validate logic flow: e.g., ensure if-else conditions are correctly implemented.

• Test edge cases: e.g., inputting maximum or minimum values.

• Review data types: e.g., ensure integers are not being compared to strings.

• Look for off-by-one errors: e.g., iterating through arrays incorrectly.

To get all the links available on a page, you can use web scraping techniques.

• Use a web scraping tool like BeautifulSoup in Python or Selenium to extract all the links from the page

• Identify the HTML elements that contain the links, such as tags with href attributes

• Iterate through the elements to extract the URLs and store them in a list

Code for nested dictionary

• Use curly braces to define the outer dictionary

• Use square brackets to define the inner dictionaries

• Access values using keys

Printing all prime numbers from 1 to N.

• Iterate from 2 to N and check if each number is prime or not.

• Use a nested loop to check if a number is divisible by any number less than it.

• If a number is not divisible by any number less than it, it is a prime number.

• Print all prime numbers found.

A linked list is a linear data structure where each element is a separate object with a reference to the next element.

• Each element in a linked list is called a node

• Nodes are connected using pointers or references

• Linked lists can be singly linked (each node points to the next) or doubly linked (each node points to the next and previous)

OOPs (Object-Oriented Programming) is a programming paradigm based on the concept of objects, which can contain data and code.

• Encapsulation: Bundling data and methods that operate on the data within one unit (e.g., a class).

• Inheritance: Mechanism where a new class inherits properties and behavior from an existing class (e.g., a 'Dog' class inheriting from an 'Animal' class).

• Polymorphism: Ability to present the same interface for different underlying data types (e.g., method o...read more

Implement LFU cache using OOPs concepts

• Create a class for LFU cache with methods like get, put, and remove

• Use a hashmap to store key-value pairs and a hashmap to store frequency of each key

• Implement a doubly linked list to store keys with the same frequency

A paradox in testing refers to a situation where a test case both passes and fails at the same time.

• Paradox in testing can occur when a test case has conflicting requirements or conditions.

• It can also happen when there are errors in the test setup or execution that lead to unexpected results.

• For example, a test case may pass when run individually but fail when run as part of a test suite due to dependencies.

• Identifying and resolving paradoxes in testing is crucial for ensurin...read more

Waits in Selenium are used to make the automation script wait for a certain condition to be met before proceeding.

• There are three types of waits in Selenium: Implicit Wait, Explicit Wait, and Fluent Wait.

• Implicit Wait sets a default waiting time for the entire script to wait for an element to be found.

• Explicit Wait is used to wait for a certain condition to occur before proceeding to the next step.

• Fluent Wait is a more flexible wait that allows you to define the maximum amoun...read more

Backward compatibility refers to the ability of a system to accept input intended for an older version of the system.

• Allows newer versions of software to work with data or systems from older versions

• Ensures that changes in the software do not break compatibility with existing data or systems

• Helps in smooth transition and adoption of new versions without disrupting existing processes

Equivalence partitioning is a software testing technique where input data is divided into partitions and only one value from each partition is tested.

• Input data is divided into groups or partitions based on similar characteristics

• One value from each partition is selected as a representative for testing

• Helps in reducing the number of test cases while ensuring maximum coverage

• Example: Testing a login form with valid, invalid, and boundary input partitions

Program to remove duplicate numbers from array of strings

• Iterate through the array and store each element in a set to keep track of unique elements

• If an element is already in the set, remove it from the array

• Return the array with duplicates removed