Krenai Services Software Developer Interview Questions and Answers

Selection sort is a simple sorting algorithm that repeatedly selects the minimum element from an unsorted portion of the array and swaps it with the first unsorted element.

• Iterate through the array to find the smallest element.

• Swap the smallest element with the first unsorted element.

• Repeat the process for the remaining unsorted portion of the array.

• Time complexity is O(n^2) and space complexity is O(1).

SQL joins are used to combine rows from two or more tables based on a related column between them.

• Joins are used to retrieve data from multiple tables in a single query.

• Types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.id = table2.id;

Procedures in SQL are reusable blocks of code that perform a specific task.

• Procedures are stored in the database and can be called multiple times.

• They can accept input parameters and return output parameters.

• Procedures can contain SQL statements, control-of-flow statements, and error handling.

• Example: CREATE PROCEDURE GetEmployeeDetails AS SELECT * FROM Employees;

• Example: EXEC GetEmployeeDetails;

Print a pyramid star pattern using nested loops.

• Use nested loops to print spaces and stars in each row

• Increment the number of stars in each row to form a pyramid shape

== is used for comparing reference equality, while .equals is used for comparing object equality in Java.

• == compares memory addresses of objects

• .equals compares the actual content of objects

• == is used for comparing primitive data types

• .equals is used for comparing objects in Java

Quick sort is a sorting algorithm that uses divide and conquer approach to sort an array efficiently.

• Divide the array into two sub-arrays based on a pivot element

• Recursively sort the sub-arrays

• Combine the sorted sub-arrays to get the final sorted array

• Example: [3, 6, 8, 10, 1, 2, 1] -> [1, 1, 2, 3, 6, 8, 10]