PHP interview Questions

1. What are the differences between Get and post methods in form submitting, give the case where we can use get and we can use post methods?

2. Who is the father of php and explain the changes in php versions?

3. How can we submit from without a submit button?

4. How many ways we can retrieve the date in result set of mysql using php?

5. What is the difference between mysql_fetch_object and mysql_fetch_array?

6. What is the difference between $message and $$message?

7. How can we extract string 'abc.com ' from a string 'http://info@abc.com' using regular expression of php?

8. How can we create a database using php and mysql?

9. What are the differences between require and include, include_once?

10. Can we use include ("abc.php") two times in a php page "makeit.php"?

11. What are the different tables present in mysql, which type of table is generated when we are creating a table in the following syntax: create table employee(eno int(2),ename varchar(10)) ?

12. Functions in IMAP, POP3 AND LDAP?

13. How can I execute a php script using command line?

14. Suppose your Zend engine supports the mode Then how can u configure your php Zend engine to support mode ?

15. Shopping cart online validation i.e. how can we configure the paypals?

16. What is meant by nl2br()?

17. Draw the architecture of Zend engine?

18. What are the current versions of apache, php, and mysql?

19. What are the reasons for selecting lamp (linux, apache, mysql, php) instead of combination of other software programmes, servers and operating systems?

20. How can we encrypt and decrypt a data present in a mysql table using mysql?

21. How can we encrypt the username and password using php?

22. What are the features and advantages of OBJECT ORIENTED PROGRAMMING?

23. What are the differences between PROCEDURE ORIENTED LANGUAGES AND OBJECT ORIENTED LANGUAGES?

24. What is the use of friend function?

25. What are the differences between public, private, protected, static, transient, final and volatile?

26. What are the different types of errors in php?

27. What is the functionality of the function strstr and stristr?

28. What are the differences between PHP 3 and PHP 4 and PHP 5?

29. How can we convert asp pages to php pages?

30. What is the functionality of the function htmlentities?

31. How can we get second of the current time using date function?

32. How can we convert the time zones using php?

33. What is meant by urlencode and urldocode?

34. What is the difference between the functions unlink and unset?

35. How can we register the variables into a session?

36. How can we get the properties (size, type, width, height) of an image using php image functions?

37. How can we get the browser properties using php?

38. What is the maximum size of a file that can be uploaded using php and how can we change this?

39. How can we increase the execution time of a php script?

40. How can we take a backup of a mysql table and how can we restore it. ?

41. How can we optimize or increase the speed of a mysql select query?

42. How many ways can we get the value of current session id?

43. How can we destroy the session, how can we unset the variable of a session?

44. How can we destroy the cookie?

45. How many ways we can pass the variable through the navigation between the pages?

46. What is the difference between ereg_replace() and eregi_replace()?

47. What are the different functions in sorting an array?

48. How can we know the count/number of elements of an array?

49. What is the php predefined variable that tells the What types of images that php supports?

50. How can I know that a variable is a number or not using a JavaScript?

51. List out some tools through which we can draw E-R diagrams for mysql.

52. How can I retrieve values from one database server and store them in other database server using php?

53. List out the predefined classes in php?

54. How can I make a script that can be bilanguage (supports English, German)?

55. What are the difference between abstract class and interface?

56. How can we send mail-using JavaScript?

57. How can we repair a mysql table?

58. What are the advantages of stored procedures, triggers, indexes?

59. What is the maximum length of a table name, database name, and fieldname in mysql?

60. How many values can the SET function of mysql takes?

61. What are the other commands to know the structure of table using mysql commands except explain command?

62. How many tables will create when we create table, what are they?

63. What is the purpose of the following files having extensions 1) frm 2) MYD 3) MYI. What these files contains?

64. What is maximum size of a database in mysql?

65. Give the syntax of Grant and Revoke commands?

66. Explain Normalization concept?

67. How can we find the number of rows in a table using mysql?

68. How can we find the number of rows in a result set using php?

69. How many ways we can we find the current date using mysql?

70. What are the advantages and disadvantages of CASCADE STYLE SHEETS?

71. What type of inheritance that php supports?

72. How can increase the performance of mysql select query?

The structure of table view buyers is as follows

+----------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------------+-------------+------+-----+---------+----------------+
| user_pri_id | int(15) | | PRI | NULL | auto_increment |
| userid | varchar(10) | YES | | NULL | |
+----------------+-------------+------+-----+---------+----------------+

the value of user_pri_id the last row 2345 then What will happen in the following conditions

Condition1: Delete all the rows and insert another row then What is the starting value for this auto incremented field user_pri_id ,
Condition2: Delete the last row(having the field value 2345) and insert another row then What is the value for this auto incremented field user_pri_id

73. What are the advantages/disadvantages of mysql and php?

74. What is the difference between GROUP BY and ORDER BY in Sql?

75. What is the difference between char and varchar data types?

76. What is the functionality of md5 function in php?

77. How can I load data from a text file into a table?

78. How can we know the number of days between two given dates using mysql?

79. How can we know the number of days between two given dates using php?

80. How can we change the name of a column of a table?

81. How can we change the name and data type of a column of a table?

82. What are the differences between drop a table and truncate a table?

83. When you want to show some part of a text displayed on an HTML page in red font color, what different possibilities are there to do this? What are the advantages/disadvantages of these methods?

84. When viewing an HTML page in a Browser, the Browser often keeps this page in its cache. What can be possible advantages/disadvantages of page caching? How can you prevent caching of a certain page (please give several alternate solutions)?

85. What are the different methods of passing data or information between two calls of a web page? What are the advantages/disadvantages of these methods?

86. An Apache web server is running on a Linux system. Suddenly, the web server delivers the pages very slow. How could you find out possible reasons for that (when using system commands, please specify their names)?

87. What are the different ways to login to a remote server? Explain the means, advantages and disadvantages?

88. Please give a regular expression (preferably Perl/PREG style), which can be used to identify the URL from within a HTML link tag. Example: The regular expression should match the tag < A HREF="http://www.yoursite.com/" > and give the URL ("http://www.yoursite.com /") as a return result. Tags should also be matched if they contain other attributes than the HREF attribute.

89. A select query over a large table runs very slow because of the growing number of entries in that table. What different measures could be taken to improve speed?

90. A company wants to store their invoices in a database. They already have their customers and articles in that database. Both customer and article are each identified by an unique integer value. Please create the SQL statements for creating the necessary table(s) for storing the invoices in a MySQL database. An invoice should hold information like invoice number, customer, date, article(s) and quantity etc.

91. For the database from the previous question, please give an SQL query which returns the invoice number of all invoices which contain the article with the number "1234". The query should be able to run under a MySQL 4.0 database.

92. How would you backup and restore a big MySQL database? What are the advantages of the approach which you have taken over the others?

93. Create a PHP web script with the following attributes: on start, three HTML form elements are shown: an string input field, a checkbox field, a dropdown/pull down list with 5 elements and a submit button. On submission, the form should be redisplayed (while remaining all options/inputs as the user has selected/entered them). Additionally, the selections/inputs of the user should be displayed in text. Please solve this without the use of any external libraries.

94. What is meant by MIME?

95. What is meant by PEAR in php?

96. How can I use the COM components in php?

97. How can I load the dll’s dynamically?

98. How many ways we can give the output to a browser?

99. How can we know that a session is started or not?

100. What is the default session time in php and how can I change it?

101. What changes I have to done in php.ini file for file uploading?

102. What are the differences between mysql_fetch_array(), mysql_fetch_object(), mysql_fetch_row()?

103. How can I set a cron and how can i execute it in Unix, Linux, and windows?

104. Steps for the payment gateway processing?

105. How many ways I can register the variables into session?

106. Explain different types of errors in php (i.e. arguments in errorreporting function)?

107. How many ways I can redirect a php page?

108. List out different arguments in php header function?

109. What type of headers have to add in the mail function in which file a attached?

110. What is the difference between
111. What are the differences between php3 and php4 versions?

112. What are the differences between include() and include_once() functions?

113. Describe the importance of DABA BASE ABSTRACTION LAYERS in php and database connection?

114. Explain mysql optimization?

115. What is the difference between using copy() and move() function in php file uploading?

116. What is the difference between Reply-to and Return-path in the headers of a mail function?

117. Explain about Type Juggling in php?

118. How can I get the only name of the current executing file?

119. How can I embed a java programme in php file and what changes have to be done in php.ini file?

120. How can I find what type of images that the php version supports?

121. The table tbl_sites contains the following data.

PHP Interview Questions

PHP Interview Questions

1) Explain about PHP?
Personal home page language is used to create dynamic and interactive websites which are very efficient in delivering client needs from the server side. This language is widely used. It is used on various operating systems with Apache modules. This can be directly embedded into HTML code.

2) Explain about the installation of PHP on UNIX systems?
PHP can be installed on UNIX in many different ways there are pre defined packages available which can ease the process. Initially it can be controlled by the command line options. Help can be obtained from./configure help command. After installing PHP modules or executables can be configures and make command should help you in the process.

3) How to enable parsing?
Parsing is an important concept if you want to run your code appropriately and timely. PHP parses all the code present between the opening and closing tags, it ignores everything present out of the closing and opening tags. This tags allow PHP to be embedded between many documents.

4) What are the different opening and closing tags available in PHP?
There are four different types of tags available in PHP they are
*
*

* PHP short tags
* ASP style tags.
Generally the first two tags are widely used because they are portable.

5) Explain about array uintersect()?
This function is very useful in PHP. This function compares array values in a user defined function and it returns the array. If assoc() is added to the function it compares array keys. This function can also be defined as array uintersect uassoc().

6) Explain about converting an object?
When an object is converted into an object the stance of the object is not modified. A new instance of the class is created if a value of different type if converted into an object. Incase the value is null at the time of conversion the new instance will be empty.

7) Explain about resource?
Resource holds reference to an external resource and it is a special variable. These are created and used by specially defined functions. Resource holds defined and special handlers for opening files. Converting to a resource makes no sense at all.

8) Explain about null?
Null represents a variable with no value inside. There doesn’t exist any value for type Null. Null is defined to be null if and only if it is assigned a constant null, there is no value set, it is set to be unset(). This is the case insensitive keyword. There are also two functions they are is_null and unset().

9) Explain about mixed and callback functions?
Mixed function indicates that the function may contain multiple types but it doesn’t form a necessary condition. Functions like call_user_func() or usort() accept user defined functions as parameter. These functions are not only simple but also object methods which includes static methods.

10) Explain about PHP looping?
Looping statements are used in PHP to execute the code for a developer defined number of times. PHP has these following looping statements they are while, do while, for and for each. Foreach is used to loop a block of code in each element in an array.

11) Explain about Booleans in PHP?
A Boolean type states a truth value whether it is true or false. These statements are case insensitive. An operator returns a Boolean value and this value is passed onto the control structure which executes the statement. If an argument is required it is automatically converted.

12) Explain about Type juggling?
PHP uses Type juggling similar to the way Perl uses. Variable is defined in the context in which it is used. It doesn’t require any explicit definition for a function to perform its duties. For example if a string value is assigned to a variable it is defined as string.

13) Explain about the casts allowed in PHP?
Type casting acts and functions similarly as it performs in C. The casts allowed are Integer, Boolean, float and double, string, binary, array and object. Casting and support was added in PHP 5.2.1. A variable can be enclosed in double quotes instead of casting it to a string.

14) How to change the principal password?
Principal password can be changed by using kadm5_chpass_principal command. If you also want to specify the new password for effecting a change to the principal password it should be as
Bool kadm5_chpass_principal (resource $handle, string $principal, string password). This changes the password to password.

15) Explain about the advantages of using PHP?
There are many advantages of PHP they are
1) Easy and fast creation of dynamic web pages and a developer can also embed these dynamic functions into HTML.
2) A huge community resource which has a ton of information before you.
3) Connectivity ability lets you to connect to different interfaces and predefined libraries.
4) Execution is very fast because it uses less system resources, etc.

16) Explain about the connective abilities of the PHP?
A huge advantage for PHP is its connective ability. It uses huge number of extensions to interface with huge pool of libraries such as XML, graphics and encryption. Programmers can create their own extensions and compiling them. They can load their own programs by using the dynamic loading mechanism.

17) How can MYSQL functions be available with PHP?
MYSQL is not available as a default feature it must be created by the user. You can use --with-mysql=DIR function to make available SQL on your system. Compiling PHP functions with MYSQL will increase the support and functioning of the language. MYSQL should be installed where there are extensions of PHP

22 Regular Questions on PHP

1. Which of the following will not add john to the users array?
2. What’s the difference between sort(), assort() and ksort? Under what circumstances would you use each of these?
3. What would the following code print to the browser? Why?
4. What is the difference between a reference and a regular variable? How do you pass by reference & why would you want to?
5. What functions can you use to add library code to the currently running script?
6. What is the difference between foo() & @foo()?
7. How do you debug a PHP application?
8. What does === do? What’s an example of something that will give true for ‘==’, but not ‘===’?
9. How would you declare a class named “myclass” with no methods or properties?
10. How would you create an object, which is an instance of “myclass”?
11. How do you access and set properties of a class from within the class?
12. What is the difference between include & include_once? include & require?
13. What function would you use to redirect the browser to a new page?
14. What function can you use to open a file for reading and writing?
15. What’s the difference between mysql_fetch_row() and mysql_fetch_array()?
16. What does the following code do? Explain what’s going on there.
17. Given a line of text $string, how would you write a regular expression to strip all the HTML tags from it?
18. What’s the difference between the way PHP and Perl distinguish between arrays and hashes?
19. How can you get round the stateless nature of HTTP using PHP?
20. What does the GD library do?
21. Name a few ways to output (print) a block of HTML code in PHP?
22. Is PHP better than Perl? – Discuss.

5 steps to create a self-signed SSL Certificate

5 steps to create a self-signed SSL Certificate


Step 1: Generate a Private Key

Command:

openssl genrsa -des3 -out server.key 1024

Step 2: Generate a CSR

Command:

openssl req -new -key server.key -out server.csr

Step 3: Generating a Self-Signed Certificate

Command:

openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt

Step 4: Installing the Private Key and Certificate

Command:

cp server.crt /usr/local/apache/conf/ssl.crt
cp server.key /usr/local/apache/conf/ssl.key

Step 5: Configuring SSL Enabled Virtual Hosts

Command: (Change this in the configuration file of apache)

SSLEngine on
SSLCertificateFile /usr/local/apache/conf/ssl.crt/server.crt
SSLCertificateKeyFile /usr/local/apache/conf/ssl.key/server.key