PHP allows us to choose whether or not to display errors to users. There are three ways to enable or disable error reporting in PHP:

Method 1: You can turn the display error parameter in the php.ini file on or off. When it’s on, errors are shown; when it’s off, there are no errors shown or reported. To do this, locate the display error parameter in the php.ini file, then set its value to “on.” Restart the web server's various services. The PHP script's errors will now be visible to end users. Set the display error parameter to “off” to stop reporting errors. The off argument indicates that users won't see any errors.

Method 2: Using the mini set() function is the second way to enable or stop error reporting. The ability to modify the configuration options in the php.ini file is a built-in feature of the PHP programming language. It requires two inputs: the name of the setting you want to change and the value you want to assign.

Method 3: You can also utilize the error reporting() function, a native PHP function, to enable error reporting. This function controls which PHP faults are reported and sets the error reporting directive during runtime. Given that PHP has multiple error levels, this method also aids in setting the various levels for the runtime (duration) of your script. This function accepts parameters for error names like E ERROR, E WARNING, E PARSE, etc., allowing these errors to be reported.

The === operator will check for a specific type, such as an integer or boolean, exactly as one would anticipate from a strongly typed language. This is in contrast to the == operator, which will temporarily transform the data and attempt to match the types of both operands.

The absence of type conversion also improves the performance of the identity operator (===). Avoid using == for determining whether a variable is true or false, as this would also consider 0/1 or other comparable representations.

There are many advantages of using a framework, but the interviewer is likely most interested in hearing about how a framework can help with development speed and organization. By using a framework, developers can take advantage of pre-built code libraries and modules which can help save time during the development process. In addition, frameworks often enforce coding conventions and standards which can help keep code more organized and maintainable.

There are a few possible reasons why an interviewer might ask this question to a senior PHP developer. One reason could be to gauge the developer's understanding of testing PHP applications. Another reason could be to see if the developer is familiar with best practices for testing PHP applications.

It is important to test PHP applications thoroughly because they can be complex and buggy. By testing the most important parts of an application, developers can ensure that the application is stable and free of errors.

There are a few things that are important to test in a PHP application:

1. The functionality of the application - This includes testing that all the features of the application work as expected.

2. The performance of the application - This includes testing how quickly the application responds to requests, how much traffic it can handle, etc.

3. The security of the application - This includes testing for vulnerabilities that could allow attackers to gain access to the system or data, or to cause Denial of Service attacks.”

• WordPress: WordPress is a free and open-source content management system (CMS) based on PHP & MySQL. It includes a plug-in architecture and template system. It is mostly connected with blogging but supports another kind of web content, containing more traditional mailing lists and forums, media displays, and online stores.
• Joomla: Joomla is a free and open-source content management system (CMS) for distributing web content, created by Open Source Matters, Inc. It is based on a model-view-controller web application framework that can be used independently of the CMS.
• Magento: Magento is an open source E-trade programming, made by Varien Inc., which is valuable for online business. It has a flexible measured design and is versatile with many control alternatives that are useful for clients. Magento utilizes E-trade stage which offers organization extreme E-business arrangements and extensive support network.
• Drupal: Drupal is a CMS platform developed in PHP and distributed under the GNU (General Public License).

• Scalar type declarations
• Return type declarations
• Null coalescing operator (??)
• Spaceship operator
• Constant arrays using define()
• Anonymous classes
• Closure::call method
• Group use declaration
• Generator return expressions
• Generator delegation
• Space ship operator