Misha Infotech Interview Questions and Answers

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

• Inner JOIN returns only the matching rows from both tables

• Equi JOIN is a type of Inner JOIN where the join condition is based on equality between two columns

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

Divide array in two halves and keep each half in ascending order without using new Array.

• Use Array.sort() method to sort the original array

• Use Array.slice() method to divide the array into two halves

• Use Array.reverse() method to reverse the second half of the array

Interfaces are contracts that define a set of methods and properties that a class must implement.

• Interfaces provide a way to achieve abstraction and polymorphism in object-oriented programming.

• They allow for loose coupling between classes and promote code reusability.

• Interfaces can be used to define common behavior across multiple classes.

• Example: IDisposable interface in C# ensures that an object can be properly dispo...read more

Inheritance is a mechanism in object-oriented programming where a class is based on another class.

• Inheritance allows a subclass to inherit properties and methods from a superclass.

• The subclass can also add its own properties and methods.

• Examples include a Car class inheriting from a Vehicle class, or a Dog class inheriting from an Animal class.

Union combines and removes duplicates, Union All combines all rows including duplicates.

• Union merges the results of two or more SELECT statements into a single result set.

• Union All returns all rows from all SELECT statements, including duplicates.

• Union requires the same number of columns in all SELECT statements, while Union All does not.

• Union sorts the result set and removes duplicates, while Union All does not.

• Union ...read more

Abstract methods are methods without implementation in abstract classes, while interfaces are contracts that define methods.

• Abstract classes can have both abstract and non-abstract methods, while interfaces can only have abstract methods.

• A class can implement multiple interfaces, but can only inherit from one abstract class.

• Abstract classes can have constructors, while interfaces cannot.

• Interfaces can have properties,

The optimal solution approach for the Travelling Salesman Problem involves using algorithms such as the Nearest Neighbor Algorithm and the 2-Opt Algorithm.

• The Nearest Neighbor Algorithm starts at a random city and selects the nearest unvisited city as the next stop.

• The 2-Opt Algorithm involves swapping two edges in the tour to see if it results in a shorter distance.

• Other algorithms include the Genetic Algorithm and th...read more

No, only one primary key can be defined in a SQL table.

• Primary key ensures uniqueness of each record in a table.

• A table can have only one primary key constraint.

• However, a composite primary key can be created using multiple columns.