Php interview Questions - part11

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

mysql_fetch_array - Fetch a result row as an associative array and a numeric array.

mysql_fetch_object - Returns an object with properties that correspond to the fetched row and moves the internal data pointer ahead. Returns an object with properties that correspond to the fetched row, or FALSE if there are no more rows

mysql_fetch_row() - Fetches one row of data from the result associated with the specified result identifier. The row is returned as an array. Each result column is stored in an array offset, starting at offset 0.

What is meant by nl2br()?

Anwser1:
nl2br() inserts a HTML tag <br> before all new line characters \n in a string.

echo nl2br("god bless \n you");

output:
god bless<br>
you

How can we encrypt and decrypt a data presented in a table using MySQL?

You can use functions: AES_ENCRYPT() and AES_DECRYPT() like:

AES_ENCRYPT(str, key_str)
AES_DECRYPT(crypt_str, key_str)

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

For this purpose, you can first read the data from one server into session variables. Then connect to other server and simply insert the data into the database.

WHO IS THE FATHER OF PHP AND WHAT IS THE CURRENT VERSION OF PHP AND MYSQL?

Rasmus Lerdorf.
PHP 5.1. Beta
MySQL 5.0

IN HOW MANY WAYS WE CAN RETRIEVE DATA IN THE RESULT SET OF MYSQL USING PHP?

mysql_fetch_array - Fetch a result row as an associative array, a numeric array, or both
mysql_fetch_assoc - Fetch a result row as an associative array
mysql_fetch_object - Fetch a result row as an object
mysql_fetch_row —- Get a result row as an enumerated array

What are the functions for IMAP?

imap_body - Read the message body
imap_check - Check current mailbox
imap_delete - Mark a message for deletion from current mailbox
imap_mail - Send an email message

What are encryption functions in PHP?

CRYPT()
MD5()

What is the difference between htmlentities() and htmlspecialchars()?

htmlspecialchars() - Convert some special characters to HTML entities (Only the most widely used)
htmlentities() - Convert ALL special characters to HTML entities

What is the functionality of the function htmlentities?

htmlentities() - Convert all applicable characters to HTML entities
This function is identical to htmlspecialchars() in all ways, except with htmlentities(), all characters which have HTML character entity equivalents are translated into these entities.

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

To know the image size use getimagesize() function
To know the image width use imagesx() function
To know the image height use imagesy() function

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

By the use of void set_time_limit(int seconds)
Set the number of seconds a script is allowed to run. If this is reached, the script returns a fatal error. The default limit is 30 seconds or, if it exists, the max_execution_time value defined in the php.ini. If seconds is set to zero, no time limit is imposed.

When called, set_time_limit() restarts the timeout counter from zero. In other words, if the timeout is the default 30 seconds, and 25 seconds into script execution a call such as set_time_limit(20) is made, the script will run for a total of 45 seconds before timing out.