- In abstract classes this is not necessary that every method should be abstract. But in interface every method is abstract.
- Multiple and multilevel both type of inheritance is possible in interface. But single and multilevel inheritance is possible in abstract classes.
- Method of php interface must be public only. Method in abstract class in php could be public or protected both.
- In abstract class you can define as well as declare methods. But in interface you can only defined your methods.
phpMyAdmin is a free and open source tool written in PHP intended to handle the administration of MySQL with the use of a web browser. It can perform various tasks such as creating, modifying or deleting databases, tables, fields or rows; executing SQL statements; or managing users and permissions.
1) Execute sudo apt-get install phpmyadmin
2) Edit the file /etc/apache2/apache2.conf. and include the line Include /etc/phpmyadmin/apache.conf
3) Restart Apache sudo /etc/init.d/apache2 reload
- Web interface
- MySQL database management
- Import data from CSV and SQL
- Export data to various formats: CSV, SQL, XML, PDF (via the TCPDF library), ISO/IEC 26300 – OpenDocument Text and Spreadsheet, Word, Excel, LaTeX and others
- Administering multiple servers
- Creating PDF graphics of the database layout
- Creating complex queries using Query-by-Example (QBE)
- Searching globally in a database or a subset of it
- Transforming stored data into any format using a set of predefined functions, like displaying BLOB-data as image or download-link
- Live charts to monitor MySQL server activity like connections, processes, CPU/Memory usage, etc.
- Working with different operating systems.
Customer sessions stores data related to customer, checkout session stores data related to quote and order. They are actuall under one session in an array. So firstname in customer/session will be $_SESSION[‘customer’][‘firstname’] and cart items count in checkout/session will be $_SESSION[‘checkout’][‘items_count’]. The reason Magento uses session types separately is because once the order gets placed, the checkout session data information should get flushed which can be easily done by just unsetting $_SESSION[‘checkout’] session variable. So that the session is not cleared, just session data containing checkout information is cleared and rest all the session types are still intact.
The “magic” methods are ones with special names, starting with two underscores, which denote methods which will be triggered in response to particular PHP events. That might sound slightly automagical but actually it’s pretty straightforward, we already saw an example of this in the last post, where we used a constructor – so we’ll use this as our first example.
PHP functions that start with a double underscore – a “__” – are called magic functions (and/or methods) in PHP. They are functions that are always defined inside classes, and are not stand-alone (outside of classes) functions. The magic functions available in PHP are: __construct(), __destruct(), __call(), __callStatic(), __get(), __set(), __isset(), __unset(), __sleep(), __wakeup(), __toString(), __invoke(), __set_state(), __clone(), and __autoload().
HTTP is a session less protocol. A connection is made to transfer a single file and closed once the transfer is complete. This keeps things simple but it’s not very efficient.
To improve efficiency something called KeepAlive was introduced. With KeepAlive the web browser and the web server agree to reuse the same connection to transfer multiple files.
Undefined value means the
- Variable used in the code doesn’t exist
- Variable is not assigned to any value
- Property doesn’t exist
document.write(“Welcome”) is used to print the text – Welcome in the screen.
‘Typeof’ is an operator which is used to return a string description of the type of a variable.
- Content is replaced everywhere
- We cannot use like “appending to innerHTML”
- Even if you use +=like “innerHTML = innerHTML + ‘html’” still the old content is replaced by html
- The entire innerHTML content is re-parsed and build into elements, therefore its much slower
- The innerHTML does not provide validation and therefore we can potentially insert valid and broken HTML in the document and break it
The pop() method is similar as the shift() method but the difference is that the Shift method works at the start of the array. Also the pop() method take the last element off of the given array and returns it. The array on which is called is then altered.