Top 120 PHP Interview Questions Asked in coding Interview 2019

PHP Interview Questions – 120 Questions

1. What is PHP?
2. What do the initials of PHP stand for?
3. Which programming language does PHP resemble?
4. What does PEAR stand for?
5. What is the actually used PHP version?
6. How do you execute a PHP script from the command line?
7. How to run the interactive PHP shell from the command line interface?
8. What is the correct and the most two common way to start and finish a PHP block of code?
9. How can we display the output directly to the browser?
10. What is the main difference between PHP 4 and PHP 5?
11. Is multiple inheritance supported in PHP?
12. What is the meaning of a final class and a final method?
13. How is the comparison of objects done in PHP?
14. How can PHP and HTML interact?
15. What type of operation is needed when passing values through a form or an URL?
16. How can PHP and Javascript interact?
17. What is needed to be able to use the image function?
18. What is the use of the function ‘imagetypes()’?
19. What are the functions to be used to get the image’s properties (size, width, and height)?
20. How failures in execution are handled with include() and require() functions?
21. What is the main difference between require() and require_once()?
22. How can I display text with a PHP script?
23. How can we display information of a variable and readable by a human with PHP?
24. How is it possible to set an infinite execution time for PHP script?
25. What does the PHP error ‘Parse error in PHP – unexpected T_variable at line x’ means?
26. What should we do to be able to export data into an Excel file?
27. What is the function file_get_contents() useful for?
28. How can we connect to a MySQL database from a PHP script?
29. What is the function mysql_pconnect() useful for?
30. How be the result set of Mysql handled in PHP?
31. How is it possible to know the number of rows returned in the result set?
32. Which function gives us the number of affected entries by a query?
33. What is the difference between mysqli_fetch_object() and mysqli_fetch_array()?
34. How can we access the data sent through the URL with the GET method?
35. How can we access the data sent through the URL with the POST method?
36. How can we check the value of a given variable is a number?
37. How can we check the value of a given variable is alphanumeric?
38. How do I check if a given variable is empty?
39. What does the unlink() function mean?
40. What does the unset() function mean?
41. How do I escape data before storing it in the database?
42. How is it possible to remove escape characters from a string?
43. How can we automatically escape incoming data?
44. What does the function get_magic_quotes_gpc() means?
45. Is it possible to remove the HTML tags from data?
46. what is the static variable in function useful for?
47. How can we define a variable accessible in functions of a PHP script?
48. How is it possible to return a value from a function?
49. What is the most convenient hashing method to be used to hash passwords?
50. Which cryptographic extension provide generation and verification of digital signatures?
51. How is a constant defined in a php script?
52. How can you pass a variable by reference?
53. How is it possible to cast types in PHP?
54. When is a conditional statement ended with endif?
55. How is the ternary conditional operator used in php?
56. What is the function func_num_args() used for?
57. What does accessing a class via :: means?
58. In PHP, objects are they passed by value or by reference?
59. Are Parent constructors called implicitly inside a class constructor?
60. What’s the difference between __sleep and __wakeup?
61. What is faster?
62. what is the definition of a session?
63. How to initiate a session in PHP?
64. How can you propagate a session id?
65. What is the meaning of a Persistent Cookie?
66. When do sessions end?
67. What is the difference between session_unregister() and session_unset()?
68. What does $GLOBALS mean?
69. What does $_SERVER mean?
70. What does $_FILES means?
71. What is the difference between $_FILES[‘userfile’][‘name’] and $_FILES[‘userfile’][‘tmp_name’]?
72. How can we get the error when there is a problem to upload a file?
73. How can we change the maximum size of the files to be uploaded?
74. What does $_ENV mean?
75. What does $_COOKIE mean?
76. What does the scope of variables mean?
77. what the difference between the ‘BITWISE AND’ operator and the ‘LOGICAL AND’ operator?
78. What are the two main string operators?
79. What does the array operator ‘===’ means?
80. What is the differences between $a != $b and $a !== $b?
81. How can we determine whether a php variable is an instantiated object of a certain class?
82. What is the goto statement useful for?
83. what is the difference between Exception::getMessage and Exception:: getLine?
84. What does the expression Exception::__toString means?
85. How is it possible to parse a configuration file?
86. How can we determine whether a variable is set?
87. What is the difference between the functions strstr() and stristr()?
88. what is the difference between for and foreach?
89. Is it possible to submit a form with a dedicated button?
90. What is the difference between ereg_replace() and eregi_replace()?
91. Is it possible to protect special characters in a query string?
92. What are the three classes of errors that can occur in PHP?
93. How can we pass the variable through the navigation between the pages?
94. Is it possible to extend the execution time of a php script?
95. Is it possible to destroy a cookie?
96. What is the default session time in PHP?
97. Is it possible to use COM component in PHP?
98. Explain whether it is possible to share a single instance of a Memcache between multiple php projects?
99. Explain how you can update Memcached when you make changes to PHP?
100. What’s the difference between the include() and require() functions?
101. How can we get the IP address of the client?
102. What’s the difference between unset() and unlink()
103. What are the main error types in PHP and how do they differ?
104. What is the difference between GET and POST?
105. How can you enable error reporting in php?
106. What are Traits?
107. Can the value of a constant change during the script’s execution?
108. Can you extend a Final defined class?
109. What are the __construct() and __destruct() methods in a php class?
110. How we can get the number of elements in an array?
111. What are the 3 scope levels available in php and how would you define them?
112. What are getters and setters and why are they important?
113. What does MVC stand for and what does each component do?
114. How does one prevent the following Warning ‘Warning: Cannot modify header information – headers already sent’ and why does it occur in the first place?
115. What are SQL Injections, how do you prevent them and what are the best practices?
116. Why would you use === instead of ==?
117. Describe the Use of “ksort” in PHP
118. What are PSRs? Choose 1 and briefly describe it.
119. What PSR Standards do you follow? Why would you follow a PSR standard?
120. How Is a Session Created? How Is a Value Set in Session? How Do You Remove Data From a Session?