Infosys Senior Systems Engineer Interview Questions, Process, and Tips

Stringbuilder and Stringbuffer are used to manipulate strings efficiently.

• Use Stringbuilder when you need to modify a string frequently.

• Use Stringbuffer when you need thread safety.

• Both classes provide methods for appending, inserting, and deleting characters.

• Example: Building a long string in a loop.

• Example: Concatenating multiple strings.

Where clause filters rows before grouping, having clause filters groups after grouping.

• Where clause is used in the SELECT statement to filter rows based on a condition.

• Having clause is used in the GROUP BY statement to filter groups based on a condition.

• Where clause is used before grouping, having clause is used after grouping.

• Where clause filters individual rows, having clause filters groups of rows.

• Example: SELECT na...read more

OOPS is a programming paradigm based on the concept of objects, which can contain data and code.

• OOPS stands for Object-Oriented Programming System

• It focuses on creating reusable code and modular programs

• It involves the use of classes, objects, encapsulation, inheritance, and polymorphism

• Example: A car can be represented as an object with properties like color, model, and methods like start, stop, and accelerate

Abstract class can have implementation while interface cannot. A class can implement multiple interfaces but can only inherit from one abstract class.

• Abstract class can have constructors while interface cannot.

• Abstract class can have non-abstract methods while interface can only have abstract methods.

• Interfaces are used for multiple inheritance while abstract classes are used for single inheritance.

• Example of abstract ...read more

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Normalization involves breaking down a database into smaller, more manageable tables

• Each table should have a primary key and only contain data that is related to that key

• Normalization helps to prevent data inconsistencies and anomalies

• There are different levels of normalization, with each level building on the ...read more