Common Interview Question Ask For Software Developer

1. What is polymorphism ? The word polymorphism means having many forms. … Real life example of polymorphism: A person at the same time can have different characteristic. Like a man at the same time is a father, a husband, an employee. So the same person posses different behaviour in different situations. This is called polymorphism.
2. Difference between class and objects ? Object is termed as an instance of a class, and it has its own state, behavior and identity. A class is an entity that determines how an object will behave and what the object will contain. In other words, it is a blueprint or a set of instruction to build a specific type of object.
3. What is static and dynamic binding ? In static binding, the function defination and the function call are linked during the compile-time whereas in dynamic binding the function calls are not resolved until runtime.
4. What does group_concat() do ? The GROUP_CONCAT() function in MySQL is used to concatenate data from multiple rows into one field. This is an aggregate (GROUP BY) function which returns a String value, if the group contains at least one non-NULL value. Otherwise, it returns NULL.
5. Difference between Overloading Vs Overriding ? Overloading occurs when two or more methods in one class have the same method name but different parameters. Overriding means having two methods with the same method name and parameters (i.e., method signature).
6. Write a query to get nth highest salary from table ? select * from(
   select ename, sal, dense_rank()
   over(order by sal desc)r from Employee)
   where r=&n;
7. Write a function that return 9 if 5 is passed as argument and return 5 if 9 is pass as argument without using conditional Statement ? function(n){ return 14 -n }
8. Write program for factorial of number using recursion ? https://www.programiz.com/c-programming/examples/factorial-recursion
9. How can you cut a round cake three times to make eight equal slices?https://riddlesbrainteasers.com/three-cuts-turn-round-cake-eight-equal-slices/
10. int a =1; a++ + a++ ? What will be the output ? Ans : 3
11. How can you make a class whose object cant be created without using Abstract or ENUM keyword ? By making constructor private or call destructor in constructor
12. Write program to check if word is palindrome or not ? https://www.geeksforgeeks.org/c-program-check-given-string-palindrome/
13. Write a program to make a string palindrome ? https://www.geeksforgeeks.org/minimum-number-appends-needed-make-string-palindrome/
14. Write a query to get count of all orders of each customer in the month of November ? select count(orders) as total , customer.name from customer inner join order on order.user_id = customer.id group by order.user_id
15. Write a query to get top 10 count of all orders of each customer in the month of November ? select count(orders) as total , customer.name from customer inner join order on order.user_id = customer.id group by order.user_id sort by count DESC limit 10
16. Tell name of different types of constructor ? Default constructor, Parameterized Constructors, Copy Constructor
17. What is multi level Inheritance ? Multilevel Inheritance in C++ Programming. … When a class is derived from a class which is also derived from another class, i.e. a class having more than one parent classes, such inheritance is called Multilevel Inheritance. The level of inheritance can be extended to any number of level depending upon the relation.
18. If a table has billion of records and it take 5 second to search a record , how can you make retrieval process fast without using normalization ? by using index
19. What is a copy constructor? A copy constructor is a member function which initializes an object using another object of the same class