Regarding DBMS, Operating System, Data Structure

What is pointer What is polymorphism What is overriding write pseudo code

On-Campus Interview Experience (Alert Enterprise) ROUND I [TECHNICAL ROUND] Motive of projects Wap for Armstrong numbers Count characters in a string Collections in java Interface in java Abstract classes in Java Exception handling Virtual function and overriding Program output in which a class has a single parameterized constructor and an object is instantiated without parameters The output of the same program where obj is instantiated with default-copy constructor SQL query to retrieve only the first four characters from the names of employees Procedures in SQL and where they are used Which variable is accessed in the for loop when the same name variable is declared globally and why? How to access a global variable when the same name variable is declared in the for loop? Difference b/w delete and truncate command? What would you prefer if you want to delete all the rows( delete command or truncate command) and why? Types of inheritance in cpp and which inheritance is not in Java and why? Diamond problem in inheritance . Difference b/w normal link and active link? What is hyperlink? Can abstract class has definition of function. What is the need of interfaces Two programs were using final keyword with function and in one program it is overridden and in another the overridden function had final keyword and the fuction was called once using base class object and once using derived class object and the output of programm was asked. 3 priest and 3 devil puzzle . 4 charged and 4 non charged batteries and a lamp lightens with 2 charged batteries, the minimum number of tries in which you are sure that lamp will light. 3 switch one bulb puzzle (only once a person caan go and check the bulb in another room) Difference between == and ===. Dml and Ddl commands. Types of function calls with example Difference Between i++ and 'i=i+1' , and which one is faster. ROUND II [TECHNICAL ROUND] Introduce yourself Wap to swap two strings without 3rd string Wap to add two numbers without using + or - operator. How will you design a login page and what are the factors you will keep in mind while creating it, how will you register and authenticate a user, how will you store the info about logins of user( whether he is currently logged in or at what time he logged in and logged out). What are views and its advantages. Virtual function and run time polymorphism. Basic create insert upadte delete commands in SQL. Collections in java. What is web application? ROUND III [HR ROUND] Introduce yourself Family bg What you think over working in team or working individually Why alert enterprises What would you prefer in smart work and hard work If any question i had