PHP Interview Questions and Answers

Part:   1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  

(Continued from previous part...)

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

There are two possible ways to bridge PHP and Java: you can either integrate PHP into a Java Servlet environment, which is the more stable and efficient solution, or integrate Java support into PHP. The former is provided by a SAPI module that interfaces with the Servlet server, the latter by this Java extension.
The Java extension provides a simple and effective means for creating and invoking methods on Java objects from PHP. The JVM is created using JNI, and everything runs in-process.

Example Code:

getProperty('java.version') . ''; echo 'Java vendor=' . $system->getProperty('java.vendor') . ''; echo 'OS=' . $system->getProperty('os.name') . ' ' . $system->getProperty('os.version') . ' on ' . $system->getProperty('os.arch') . ' '; // java.util.Date example $formatter = new Java('java.text.SimpleDateFormat', "EEEE, MMMM dd, yyyy 'at' h:mm:ss a zzzz"); echo $formatter->format(new Java('java.util.Date')); ?>

The behaviour of these functions is affected by settings in php.ini.
Table 1. Java configuration options
Name
Default
Changeable
java.class.path
NULL
PHP_INI_ALL
Name Default Changeable
java.home
NULL
PHP_INI_ALL
java.library.path
NULL
PHP_INI_ALL
java.library
JAVALIB
PHP_INI_ALL

How To Turn On the Session Support?

The session support can be turned on automatically at the site level, or manually in each PHP page script:

• Turning on session support automatically at the site level: Set session.auto_start = 1 in php.ini.
• Turning on session support manually in each page script: Call session_start() funtion.

Explain the ternary conditional operator in PHP?

Expression preceding the ? is evaluated, if it’s true, then the expression preceding the : is executed, otherwise, the expression following : is executed.

What’s the difference between include and require?

It’s how they handle failures. If the file is not found by require(), it will cause a fatal error and halt the execution of the script. If the file is not found by include(), a warning will be issued, but execution will continue.

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

session_id() returns the session id for the current session.

How can we destroy the cookie?

Set the cookie in past.

How To Read the Entire File into a Single String?

If you have a file, and you want to read the entire file into a single string, you can use the file_get_contents() function. It opens the specified file, reads all characters in the file, and returns them in a single string. Here is a PHP script example on how to file_get_contents():

<?php
$file = file_get_contents("/windows/system32/drivers/etc/services");
print("Size of the file: ".strlen($file)."\n");
?>

This script will print:

Size of the file: 7116

Part:   1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20