PHP OOP EBOOK
working with objects using php's built-in OOP capabilities. At the same time OOP is all about creating modular code, so our object oriented PHP code will be. The concept of object-oriented programming may seem daunting. a comprehensive ebook to help you get started with object-oriented PHP. the PDF version. OOP – Learn Object Oriented Thinking OOP – Learn Object Oriented Th.. Download Object Oriented Programming in C++ 4th Edition by.
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Editorial Reviews. From the Author. This book was written as a learning exercise: at the time of Kindle Store; ›; Kindle eBooks; ›; Computers & Technology. Add Ebook to Cart This is not a beginner's guide to OOP PHP. I've been a developer for over 8 years now, and PHP has almost always. This book acts as a guide to using mature OOP practices in modern PHP to build and Learn more about Leanpub's ebook formats and where to read them.
But, new what? The new element that needs to be created is the instance of the class. It's good practice to add the brace on a new line. Then you need the add the properties and after that add the methods that the class requires. Do not be intimidated by this symbol, it is just a syntax of the PHP language to get the element you want to select.
You can also instantiate different buildings and this is one of the biggest pros of using OOP rather than procedural programming. Since properties and methods dwell in two different namespaces, you can create a property and a method with the same name and they will not conflict. I like to think of them as the actions that your class can perform. The Qt4 library gives a nice example for the usage. The QPainter class has three methods to draw a rectangle. Their name is drawRect and their parameters differ.
OOP in PHP and MVC
One takes a reference to a floating point rectangle object, another takes a reference to an integer rectangle object and the last one takes four parameters, x, y, width, height. The solution with method overloading is more elegant. But this does not work in PHP. Running this example, we get the following error: 'Fatal error: Cannot redeclare Sum::getSum '.
PHP functions can take arbitrary number of variables by default. PHP constructor A constructor is a special kind of a method. It is automatically called when the object is created. The purpose of the constructor is to initiate the state of the object. This class has a constructor that prints message to the console. We get a message in the console.
Constructors often take arguments. We pass a value to the constructor. In the next example, we initiate data members of the class. Initiation of variables is a typical job for constructors. The private keyword is an access modifier.
It is a form of encapsulation. The private keyword is the most restrictive modifier. It allows only the object in question to access the variable.
No descendants, no other objects. More about this topic later. Then we call the getInfo method of the object. These constants do not belong to a concrete object. They belong to the class.
By convention, constants are written in uppercase letters.
In the first case, we get the constant value by referring to the class name, followed by two colons and a constant name. Note that no object was needed to get the class constant. In the second case, we use the object method. PHP instanceof keyword The instanceof keyword is used to determine whether a PHP variable is an instantiated object of a certain class.
We traverse the array and print the class for each array value. At this point, we don't know the class types for the values of the array. We will demonstrate this in the following example.
PHP inheritance The inheritance is a way to form new classes using classes that have already been defined. The newly formed classes are called derived classes, the classes that we derive from are called base classes. Important benefits of inheritance are code reuse and reduction of complexity of a program.
The derived classes descendants override or extend the functionality of base classes ancestors. The Derived class inherits from the Base class.
The constructors of the parent classes must be called explicitly.
A more complex example follows. In the code example, we have three classes: Being, Animal, and Cat. The Animal class inherits from the Being class. The Cat class inherits from the Animal class. Classes inherit methods and data members that are not declared as private. The abstract keyword prohibits instantiation of classes. It does not make much sense to create an instance of the class Being.
Such members can be accessed only by the classes that define them and by their descendants. It inherits from class Being. For this, we use the extends keyword. The Animal is a descendant. It inherits methods and variables of the base Being class. It inherits from the Animal class and indirectly from the Being class too.
It is not declared abstract, which means that we can instantiate it. Then we call functions on the cici object.
Object-oriented programming in PHP
Note the usage of methods that were not created in the Cat class, but rather inherited from the parent classes. Abstract classes cannot be instantiated. If a class contains at least one abstract method, it must be declared abstract too. Abstract methods cannot be implemented, they merely declare the methods' signatures. A pop up confirmation will be shown. If the user clicks "OK" the record will be deleted and gone in the table.
A record was deleted in the database. This will answer the question: How to search data from database in php?
This is a very useful feature because you enable your users to easily search a certain data from our MySQL database.
Please note that this is a bonus section.
Our index. We need it because exactly the same code can be used by index. Using a template means lesser code. This template holds our search form as well. Inside that folder, create a new file and name it "core.
This file will hold our pagination variables. Using a core. Open core. The new index.
This file will display the records based on a user's search term. Create a new file and name it "search. Add the following methods in the class. Change that line to the following code. The "enctype" enables the form to submit a file to the server.
Add the following code. This adds an input field where the user can browse the file he wants to upload. The value will be the file name of the submitted file.
Find the "create " method.Each object can receive messages, send messages, and process data. Polymorphism is the process of using an operator or function in different ways for different data input.
No descendants, no other objects.
Most PHP errors still use the old error reporting and not exceptions. First, we create a class. An interface can also extend any number of interfaces. We echo the object. We get an error "Cannot override final method Base::say ".