20+ SA Infrastructure Consultants Interview Questions and Answers

Program to find second largest number from set of array

• Sort the array in descending order

• Return the second element of the sorted array

Program to check if a string is a palindrome or not.

• Create a function to compare the original string with its reverse.

• Ignore spaces and punctuation when checking for palindrome.

• Example: 'racecar' is a palindrome, 'hello' is not.

Question on stack implementation, difference between stack and linked list, and merge sort algorithm.

• Stack is a LIFO data structure while linked list is a linear data structure.

• Stack is implemented using arrays or linked lists while linked list is implemented using pointers.

• Merge sort is a divide and conquer algorithm that divides the input array into two halves, sorts them separately, and then merges them.

• Merge sort has a time complexity of O(nlogn) and is a stable sorting a...read more

OOPS concepts are the principles of Object-Oriented Programming that help in creating modular and reusable code.

• OOPS stands for Object-Oriented Programming System

• It includes concepts like Inheritance, Polymorphism, Encapsulation, and Abstraction

• Inheritance allows a class to inherit properties and methods from another class

• Polymorphism allows objects to take on multiple forms or behaviors

• Encapsulation is the practice of hiding data and methods within a class

• Abstraction is the ...read more

Protected, private and public are access modifiers in object-oriented programming that control the visibility of class members.

• Public members are accessible from anywhere in the program.

• Private members are only accessible within the class they are declared in.

• Protected members are accessible within the class they are declared in and any subclasses.

• Access modifiers are used to enforce encapsulation and prevent unauthorized access to class members.

A program to reverse a string by iterating through the characters and appending them in reverse order.

• Create a function that takes a string as input

• Initialize an empty string to store the reversed string

• Iterate through the characters of the input string in reverse order and append them to the empty string

• Return the reversed string

Program to find second maximum number in an array of strings.

• Convert array elements to integers for comparison.

• Sort the array in descending order.

• Return the second element in the sorted array.

Regression in machine learning is a technique used to predict continuous numerical values based on input data.

• Regression models are used to analyze the relationship between variables and predict outcomes.

• Linear regression is a common type of regression used in machine learning.

• Examples of regression in machine learning include predicting housing prices based on features like location and square footage, or predicting stock prices based on historical data.

• Regression can also b...read more

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

• OOP focuses on creating objects that interact with each other to solve problems

• Objects have attributes (data) and methods (functions)

• Encapsulation, inheritance, and polymorphism are key principles of OOP

• Examples of OOP languages include Java, C++, and Python

Encapsulation, Inheritance, Polymorphism, Abstraction are the 4 pillars of OOP

• Encapsulation: Bundling data and methods that operate on the data into a single unit. Example: Class in Java

• Inheritance: Ability of a class to inherit properties and behavior from another class. Example: Subclass extending a superclass

• Polymorphism: Ability to present the same interface for different data types. Example: Method overloading in Java

• Abstraction: Hiding the complex implementation details...read more

OOP is Object-Oriented Programming. OS is Operating System. SQL joins and insert queries are used to manipulate data in databases.

• OOP is a programming paradigm that focuses on objects and their interactions.

• OS is a software that manages computer hardware and software resources.

• SQL joins are used to combine data from two or more tables based on a related column.

• Insert queries are used to add new data to a table in a database.

Compile time polymorphism is resolved at compile time, while run time polymorphism is resolved at run time.

• Compile time polymorphism is achieved through function overloading and operator overloading.

• Run time polymorphism is achieved through function overriding and virtual functions.

• Compile time polymorphism is faster as the resolution is done at compile time.

• Run time polymorphism allows dynamic binding of functions based on the object type at run time.

• Compile time polymorphis...read more

A jagged array is an array of arrays where each element can be of different sizes.

• Each sub-array can have a different number of elements

• Useful for representing data structures like matrices or tables

• Example: [['apple', 'banana'], ['orange', 'grape', 'kiwi']]

Software Development Lifecycle is a process followed by software development teams to design, develop and maintain software.

• It includes phases like planning, analysis, design, implementation, testing, deployment, and maintenance.

• Each phase has its own set of activities and deliverables.

• It helps in ensuring that the software is developed efficiently and meets the requirements of the stakeholders.

• Examples of SDLC models are Waterfall, Agile, and DevOps.

Constructors are special methods in a class that are used to initialize objects.

• Constructors have the same name as the class they belong to.

• They are called automatically when an object is created.

• Constructors can have parameters to initialize object properties.

• They do not have a return type.

• Example: public class Car { public Car(String color) { this.color = color; }}

Questions related to programming concepts and database management systems.

• OOPs stands for Object-Oriented Programming which is a programming paradigm based on the concept of objects.

• Encapsulation is the process of hiding the implementation details of an object from the outside world.

• Polymorphism is the ability of an object to take on many forms.

• Runtime and compile time are two phases of program execution.

• DBMS stands for Database Management System which is a software system us...read more

DELETE removes specific rows from a table while TRUNCATE removes all rows and resets the table.

• DELETE is a DML command while TRUNCATE is a DDL command.

• DELETE can be rolled back while TRUNCATE cannot be rolled back.

• DELETE is slower than TRUNCATE as it logs each row deletion while TRUNCATE does not.

• DELETE can have WHERE clause while TRUNCATE cannot have WHERE clause.

• DELETE does not reset the identity of the table while TRUNCATE resets the identity of the table.

A program that identifies prime numbers.

• A prime number is a number that is only divisible by 1 and itself.

• The program should take an input number and check if it is prime.

• One way to check for prime numbers is to divide the number by all numbers less than it.

• If the number is only divisible by 1 and itself, it is prime.

Call by value passes a copy of the value, while call by reference passes the memory address of the value.

• Call by value creates a new copy of the value being passed.

• Call by reference passes the memory address of the value being passed.

• Changes made to the parameter in call by value do not affect the original value.

• Changes made to the parameter in call by reference affect the original value.

A program that checks if a given string is the same when read forwards and backwards.

• A palindrome can be a word, phrase, number, or other sequence of characters.

• The program should remove any spaces and punctuation before checking for palindrome.

• Examples of palindromes include 'racecar', 'level', and 'A man, a plan, a canal, Panama!'

Union combines and removes duplicates from two or more tables, while Union ALL combines all rows from two or more tables.

• Union removes duplicates, Union ALL does not

• Union requires the same number of columns in each table, Union ALL does not

• Union is slower than Union ALL

• Example: SELECT column1 FROM table1 UNION SELECT column1 FROM table2

• Example: SELECT column1 FROM table1 UNION ALL SELECT column1 FROM table2

Arrays are a collection of similar data types. They are used to store and access multiple values using a single variable.

• Arrays can be of different types such as integer, float, character, etc.

• Arrays are declared with a fixed size and can be accessed using index numbers.

• Example: int arr[5] = {1, 2, 3, 4, 5};

• Arrays can also be of strings, which are essentially arrays of characters.

• Example: char str[10] = 'Hello';

OOP stands for Object-Oriented Programming. It is a programming paradigm based on the concept of objects.

• OOP focuses on creating objects that contain both data and methods to manipulate that data.

• Encapsulation: Objects hide their internal state and require interaction through defined interfaces.

• Inheritance: Objects can inherit attributes and methods from parent classes.

• Polymorphism: Objects can take on multiple forms and behave differently based on their data type.

• Example: In...read more

Bubble sort is a simple sorting algorithm that repeatedly steps through the list, compares adjacent elements and swaps them if they are in the wrong order.

• Compare adjacent elements and swap them if they are in the wrong order

• Repeat this process until the list is sorted

• Time complexity is O(n^2)

• Example: [5, 3, 8, 4, 2] -> [3, 5, 8, 4, 2] -> [3, 5, 4, 8, 2] -> [3, 5, 4, 2, 8] -> [3, 4, 5, 2, 8] -> [3, 4, 2, 5, 8] -> [3, 4, 2, 5, 8] -> [3, 2, 4, 5, 8] -> [2, 3, 4, 5, 8]