Tregona It Consulting Interview Questions and Answers

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

• OOPS is based on four main concepts: encapsulation, inheritance, polymorphism, and abstraction.

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

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

• Polymorphism allows objects of different classes to be treated as if they were of the same...read more

Join queries in MySQL databases allow you to combine data from multiple tables based on a related column.

• Use JOIN keyword to combine data from two or more tables based on a related column

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

• Specify the columns to be retrieved using SELECT statement

Find missing element in array of strings

• Iterate through the array and check for missing elements

• Use a hash map to keep track of elements present in the array

• Compare the elements in the array with a reference array to find the missing element

Program to reverse a list

• Create an empty list to store the reversed elements

• Iterate through the original list in reverse order

• Append each element to the new list

• Return the new list

Swap two numbers without using a third variable in Java

• Use XOR operation to swap two numbers without using a third variable

• Example: int a = 5, b = 10; a = a ^ b; b = a ^ b; a = a ^ b; // Now a = 10, b = 5

map creates a new array with the results of calling a provided function on every element, forEach executes a provided function once for each array element.

• map returns a new array with the results of the provided function, forEach does not return anything

• map does not modify the original array, forEach can modify the original array

• Example: const numbers = [1, 2, 3]; numbers.map(num => num * 2); // returns [2, 4, 6]; numbers.forEach(num => console.log(num)); // prints 1, 2, 3

Fibonacci series is a sequence of numbers where each number is the sum of the two preceding ones.

• Start with two initial numbers, usually 0 and 1

• Add the previous two numbers to get the next number in the sequence

• Repeat this process to generate the Fibonacci series