DesignTech Systems Interview Questions and Answers

Truncate, delete, and drop are SQL statements used to remove data or objects from a database.

• Truncate: Removes all rows from a table without logging individual row deletions. It is faster than delete but cannot be rolled back.

• Delete: Removes specific rows from a table based on a condition. It logs individual row deletions and can be rolled back.

• Drop: Removes an entire table, view, index, or database from the database schema. It cannot be rolled back.

find element is a method in Selenium used to locate a single web element on a webpage, while find elements is used to locate multiple web elements.

• find element returns a single web element based on the locator strategy provided

• find elements returns a list of web elements based on the locator strategy provided

• Example: driver.findElement(By.id("elementId")) vs driver.findElements(By.className("elementsClass"))

Abstract class is a class that cannot be instantiated, while abstract method is a method without implementation.

• Abstract class can have both abstract and non-abstract methods, while abstract method must be inside an abstract class.

• Abstract class can have constructors, while abstract method cannot have a body.

• Abstract class can have variables, while abstract method cannot have a body.

Program to reverse a string using array of characters

• Create an array of characters to store the input string

• Iterate through the input string and store each character in the array

• Iterate through the array in reverse order to construct the reversed string

init() function is a method used in programming to initialize an object or set up initial values.

• init() function is commonly used in object-oriented programming languages like Java and Python.

• It is called automatically when an object is created.

• The init() function is used to set default values, allocate memory, or perform any other necessary setup for an object.

Our business is a technology company specializing in developing software solutions for businesses.

• Specializes in developing software solutions for businesses

• Uses technology to improve business operations

• Provides consulting services for implementing software solutions

I have used techniques like one-hot encoding, feature scaling, polynomial features, and interaction terms for feature engineering.

• One-hot encoding for categorical variables

• Feature scaling for numerical variables

• Polynomial features for capturing non-linear relationships

• Interaction terms for capturing interactions between features