10+ LTIMindtree Software Engineer Trainee Interview Questions and Answers

Credit card numbers should be stored securely using encryption and hashing algorithms.

• Use encryption and hashing algorithms to store credit card numbers securely

• Never store the full credit card number, only store the last 4 digits for identification purposes

• Use a secure database to store the credit card information

• Implement strict access controls to limit who can access the credit card information

There are five types of data types in SQL: numeric, character, date/time, Boolean, and binary.

• Numeric data types include integer, decimal, and float.

• Character data types include char, varchar, and text.

• Date/time data types include date, time, and timestamp.

• Boolean data type includes true/false values.

• Binary data type includes binary and varbinary.

A database is a collection of data that is organized and stored for easy access and retrieval.

• A database is used to store and manage data.

• It can be accessed and manipulated using specific software.

• Examples include MySQL, Oracle, and MongoDB.

CRUD stands for Create, Read, Update, and Delete operations in SQL.

• Create - INSERT statement to add new data to a table

• Read - SELECT statement to retrieve data from a table

• Update - UPDATE statement to modify existing data in a table

• Delete - DELETE statement to remove data from a table

List and tuple are both used to store collections of data, but they differ in their mutability and syntax.

• Lists are mutable, while tuples are immutable

• Lists are defined using square brackets [], while tuples use parentheses ()

• Lists are typically used for collections of similar items, while tuples are used for grouping related data

• Lists can be modified by adding, removing, or changing elements, while tuples cannot be modified once created

Use ORDER BY clause to sort first 3 records of a SQL column.

• Use ORDER BY clause followed by the column name to sort the records.

• Use LIMIT 3 to limit the results to the first 3 records.

• Example: SELECT * FROM table_name ORDER BY column_name LIMIT 3;

Null pointer exception occurs when a program tries to use a null object reference.

• It is a runtime error in Java and other programming languages.

• It happens when a program tries to access an object or variable that is null.

• It can be prevented by checking for null values before using them.

• Example: int x = null; System.out.println(x); will throw a null pointer exception.

Abstraction is the concept of hiding complex details and showing only the essential features of an object.

• Abstraction allows us to focus on what an object does, rather than how it does it

• It helps in reducing complexity and improving efficiency

• Example: A car dashboard abstracts the internal workings of the car and provides only essential information to the driver

Sorting an array of strings using C++.

• Use the std::sort function from the header.

• Define a custom comparison function if needed.

• Example: std::sort(arr.begin(), arr.end());

Inheritance is a concept in object-oriented programming where a class inherits attributes and methods from another class.

• Allows a class to inherit attributes and methods from another class

• Promotes code reusability and reduces redundancy

• Creates a parent-child relationship between classes

• Derived class can access all public and protected members of the base class

• Example: Class 'Car' can inherit from class 'Vehicle' to reuse common attributes like 'color' and 'speed'