Gainsight Sdet Interview Questions and Answers

Hashtable is synchronized while hashmap is not.

• Hashtable is thread-safe while hashmap is not.

• Hashtable does not allow null keys or values while hashmap allows one null key and multiple null values.

• Hashtable is slower than hashmap due to synchronization.

• Hashtable is a legacy class while hashmap is a newer implementation.

Hashmap is not thread-safe while Concurrent Hashmap is thread-safe.

• Hashmap is not suitable for multi-threaded environments as it can lead to race conditions and data inconsistencies.

• Concurrent Hashmap allows multiple threads to access and modify the map concurrently without any data inconsistencies.

• Concurrent Hashmap uses a technique called lock striping to achieve thread-safety.

• Concurrent Hashmap is slower than Hashma...read more

Java is an object-oriented language while C is a procedural language.

• Java is platform-independent while C is platform-dependent.

• Java has automatic garbage collection while C requires manual memory management.

• Java has built-in support for multithreading while C requires external libraries.

• Java has a larger standard library compared to C.

• Java is more secure than C due to its strong type checking and exception handling.

• C ...read more

Aggregation functions are used to perform calculations on groups of data in a database.

• Aggregation functions include COUNT, SUM, AVG, MAX, and MIN.

• They are used with the GROUP BY clause to group data based on a specific column.

• COUNT function returns the number of rows in a table or the number of non-null values in a column.

• SUM function returns the sum of values in a column.

• AVG function returns the average of values in ...read more

Two ways to write a sentence in mirror image form in Java: reverse string function and array conversion.

• Use the reverse() method of the String class to reverse the sentence

• Convert the sentence to a character array, then swap the first and last characters, second and second-to-last characters, and so on until the middle is reached

• Example: 'Hello World' becomes 'dlroW olleH'

Static is used in public static void main to allow the method to be called without creating an instance of the class.

• Static methods belong to the class and not to any instance of the class.

• The main method is the entry point of a Java program and needs to be called without creating an object of the class.

• The static keyword allows the main method to be called directly from the class, without creating an instance of the c...read more

Abstract classes, interfaces, and enums provide abstraction and modularity in Java.

• Abstract classes provide a partial implementation of a class and cannot be instantiated.

• Interfaces define a set of methods that a class must implement and can be used for multiple inheritance.

• Enums provide a set of named constants.

• All three are used for abstraction and modularity in Java.

• Abstract classes and interfaces are used for polym...read more

Object-oriented software engineering is a framework for designing and developing software using objects.

• Object-oriented software engineering is a methodology for designing and developing software using objects.

• It involves creating classes and objects that encapsulate data and behavior.

• Frameworks are pre-built structures that provide a foundation for building software applications.

• Frameworks can include libraries, APIs,...read more

Java is an object-oriented language with features like inheritance, encapsulation, and polymorphism.

• Inheritance allows classes to inherit properties and methods from other classes.

• Encapsulation hides the implementation details of a class from other classes.

• Polymorphism allows objects to take on multiple forms or behaviors.

• Java also supports abstraction, interfaces, and exception handling.

• Example: class Car extends Vehi...read more

Normalization is a process of organizing data in a database to reduce redundancy and dependency.

• Normalization is used to eliminate data redundancy and improve data integrity.

• It involves dividing a database into two or more tables and defining relationships between them.

• There are different levels of normalization, such as first normal form (1NF), second normal form (2NF), and so on.

• Normalization helps in efficient data ...read more

ADBMS stands for Advanced Database Management System which is an extension of DBMS with additional features.

• ADBMS has advanced features like data mining, data warehousing, and online analytical processing.

• ADBMS is used for handling large and complex data sets.

• DBMS is a basic system for managing data and is used for small and simple data sets.

• DBMS does not have advanced features like ADBMS.

• Examples of ADBMS are Oracle, ...read more

I am a software engineer with 5 years of experience in developing web applications.

• Proficient in programming languages such as Java, Python, and JavaScript

• Experience in developing RESTful APIs and microservices

• Familiarity with front-end technologies such as HTML, CSS, and React

• Strong understanding of database management systems like MySQL and MongoDB

• Experience in Agile development methodologies

I want to gain practical experience and contribute to the industry while also learning on the job.

• I believe that hands-on experience is invaluable in the software engineering field

• I am eager to apply my skills and knowledge to real-world projects

• I am excited to work with a team and learn from experienced professionals

• I am not currently pursuing post-graduation as I feel that gaining industry experience is more importan...read more

I would leverage my Java skills to quickly learn .NET and demonstrate my adaptability and problem-solving abilities.

• Identify transferable skills: Both Java and .NET share object-oriented principles, making it easier to adapt.

• Engage in self-study: Utilize online resources like Microsoft Learn or Pluralsight to gain .NET knowledge.

• Build a small project: Create a simple application using .NET to showcase my ability to lea...read more

I am proficient in Java, Python, and C++. I have 2 years of experience in software development. I have excellent communication skills for client interaction.

• Proficient in Java, Python, and C++

• 2 years of software development experience

• Excellent communication skills for client interaction