Interview Question

Q1. Difference between threads and process?
Q2. how threading works at CPU level?
Q3. Idea about thrashing?
Q4. List page replacement policies?
Q5. what data structure uses FIFO?
Q6. How paging works ?
Q7. what are page faults?
Q8. what is ATM?
Q9. Have you ever made a thread based program in c?
Q10. Let suppose there is a large file of about 1PB ( = 1000TB ) and you want to read it using 4 threads. How it these threads would work.
I said about Sync but he asked in a bit details.
Q11. A large linked list is given with a pointer to a middle node. How would you delete that node ?

Q12. He asked about what Internet Technologies I have worked on ?
I listed html,css,php,js,jquery,ajax
Q13. how the server works ? what server you used ? ( i said apache )
Q14. Is server a process or a thread.
I just guessed that the server is a process that is continuously listening to a port and when a request comes through the network it creates a thread for it which invokes the interpreter to execute php
Q15. He asked difference between compiler & interpreter ? can php be compiled ?
Answer :
The PHP language is interpreted. The binary that lets you interpret PHP is compiled, but what you write is interpreted.
Q16. are you comfortable with php ? ( after yes )

$a = 2;
if( $a = 3 )

echo “Hello”;
else
echo “False”;

Output ?
Q17. What is Ajax ?
Q18. how the ajax works ? tell me about headers ?
Q19. What is an IP Address and of how many bits ?

Answer - Ip address is Internet Protocol address which has IPv4(old version) is of 32-bits and IPV6- new version is of 128-bits

Q20. what is network addressing ? your networks would have a public id address then who manages the internal networks ip addresses ?

Q21. What are relational databases ? why we use relational databases ? Have you worked over NoSQL ?

Q22.  What is Left Inner Join ? Write C code for Left Inner Join if the two tables are given in form of arrays.
Q23.  What is difference between Unique Key and Primary Key.
Q24. What are Web Sockets ? ( I mentioned this in my Resume so he asked )What is Socket Programming ?

Q25. What UDP has advantages over TCP.
Q26. What is HTTP ?
Q27. How HTTP request transfers form Client to Server ? What are the headers associated with it ?
Q28. Reverse of a Linked List?
Q29. What is MVC framework ? Tell me about it’s workflow ? ( Resume Question )
Q30. What is JSON ? What is XML ?
Q31. Write a sample JSON and XML. Which one is better ? What are the advantages of JSON over XML!


Q1. Implement queue with the help of two stacks.
Q2. Given a table “student” of with columns Name and Marks. You have to write a SQL query to get the 2nd highest marks from the table. Also write a query to find the nth highest marks, where n can be any number.
Q3. What is left join. Give example. And Full outer join?
Q4. What is magic functions and autoloading in PHP?

Q1. Given three arrays sorted in non-decreasing order, print all common elements in these arrays.
Examples:
ar1[] = {1, 5, 10, 20, 40, 80}
ar2[] = {6, 7, 20, 80, 100}
ar3[] = {3, 4, 15, 20, 30, 70, 80, 120}
Output: 20, 80
Q2. A puzzle. You will be given with a 3 Litre container & a 7 Litre Container. Measure exactly 5 Litres of water.

Q1. Asked about one of my projects I mentioned in my resume?
Q2. Find if a number is a power of 2 or not?

Overall it was a very good experience. They test


Round 1:

Q1. Find the first non repetitive character in a string?
Q2. What is connection pooling.
Q3. Write a singleton class in php?

Round 2:

Q1. How to write a Connection class to MySQL database using PHP?
Q2. What are the different types of error in php?
Q3. How session works in php?
Q4. Find missing element in an array of elements from 0 to n-1?


Round 1:

Q1. Given a no K and an array. Find pair of elements whose sum is equal to given no K.
Q2. If there is a website run by 2 servers. These 2 servers balances the load using Load Balancer. So, if 1 session is created on 1 server and say load is shift to another server immediately, then how session is maintained?
Q3. WAP to implement some basic Design Patterns like Singleton?
Q4. Abstract class? How it is different from interface? Is multiple inheritance possible in php? How?
Q5. Write a stored procedure from a given set of tables and conditions. Simple one.

Round 2:

Q1. How to increase php memory at run time, if it exhausts?
Q2. What all we can do with php.ini?
Q3. session and cookies?
Q4. Javascript clausers?
Q5. Jquery function to get domain from a url?

Round 3:

Q1. WAP to get smallest plindron number larger than the given no?
Q2. WAP to check if linked list elements is a palindrome without using any extra space?



Round 1:

Q1. If your Apache web server is serving pages slowly, how would you troubleshoot the problem?

Q2. How many times can you include a php file in another php file?

Q3. What is ob_start(); used for? Why would you use it when developing web pages?

Q4. What is a table index? Why would you use it? Diff types of index?

Q5. If there is some code change in you java script file and browser is still displaying the old one what might be the reason? How to avoid it? WHat are differnet appraches other than renaming the file?

Round 2:

Q1. What are benifits of minifying the java script code?

Q2. Why java doesn’t support multiple inheritence?

Q3. Abstract class and interface?

Q4. Difference between http and https? Secure web architecture?

Q5. Describe how you would extract data from a web service if it returns JSON?



Round 3 (From US some one will take on skype):

Q1. Sql injection, Xss attack?

Q2. Write a function which will tell angle between hours hand and minute hands of clock?

Q3. Do you have experience with JavaScript frameworks? Which ones? Which one do you like the most? Why?

Q4. You have a table with an unknown number of records. You want to delete half of the records. You don’t care which records are deleted. What’s the most efficient way to do it?


It contains 4 questions.
Q1. An array and a number is given. You have to find the no with the min difference with this number?
Q2. Email and Mobile Number validation check regex?
Q3. mysql query question on self join?
Q4. A class and object architecture based on given scenario?

Technical Questions :-

Q1. What is the difference between get and post?
Q2. What is session in php?
Q3. Where does session id is stored in php? How server identifies request has come from which client and many other related questions?
Q4. Cookie in php? Size of the cookie, expiry etc?
Q5. Memcache?
Q6. Myisam and Innnodb?
Q7. Triggers in mysql?
Q8. Overriding and Overloading?
Q9. Static class and static variable?
Q10. Singleton pattern and factory pattern?
Q11. Can constructor be declared as private?
Q12. Indexing in mysql?