Asked  7 Months ago    Answers:  5   Viewed   33 times

I would like to learn PHP and want to get an Idea about OOP and Procedural. I read some other blogs and tutorials about OOP vs Procedural but I still can't understand the approach.

OOP vs Procedural

  1. Which I should learn?
  2. What is the difference in code? What are the effects?
  3. How can a PHP framework help in OOP aproach? (I would like to learn CodeIgniter)
  4. Does procedural need a Framework?

I really want to know the code difference of the both, my understanding of OOP is you create a class like and it can be access. (I don't know if that is correct).



Background: You asked for a "simple explanation" which suggests:

  1. You want a no-nonsense overview without jargon
  2. You want something that will help you learn from the beginning
  3. You have discovered that no two people ever answer the question the same way, and it's confusing. That's the reason you are here asking for a simple explanation. Yes?

Short No-Jargon Answer:

  1. Many introductory explanations jump quickly into "OOP real world" examples. Those can tend to confuse more than help, so feel free to ignore that for now.
  2. You can think of source code simply as "chunks" of functionality, that just happen to be saved to individual files.
  3. There are different ways of organizing those "chunks"; depending on things like conventions of the programming language, the background and training of the developer(s), or just plain old personal preference.
  4. OOP and Procedural programming are simply two main, generally-recognized methodologies, for how to organize and arrange those "chunks" of code.

Long No-Jargon Answer:

Procedural vs OOP is just one aspect of a fundamental issue of computer programming: how to make your code easy to understand and a piece of cake to professionally maintain. You can actually write "Procedural" code that follows some of the principles of OOP, so the two are not necessarily opposites.

Your understanding will really grow once you learn other object-oriented programming languages, among which, PHP is a "new kid on the block".

Here is a quick overview of what you will learn as you build experience:

  • You can write PHP source code that does useful tasks

  • You can organize useful tasks into "chunks" of code

  • You can think of "chunks" of code independently of the individual files where they are saved

  • Sometimes those "chunks" of code will behave differently based on parameters you pass in

  • Chunks of code that accept parameters are called "Functions"

  • Functions can be "chunked" together, and there are different ways of doing this:

    • For example: you could have just one big PHP file with all the functions you have ever written in your entire life, listed in alphabetical order by function name
    • For example: you could have multiple PHP files with functions that are chunked together by subject matter [e.g., functions for doing basic string manipulation, functions for processing arrays, functions for file input/output, etc]
  • OOP is a special way of "chunking" Functions together into a "Class"

  • A Class is just another level of "chunking" code together so that you can treat it as a unified whole

  • A Class can be thought of as a "chunking" of methods and properties

    • methods are simply functions that are logically related to one another in some meaningful way. The words "method" and "function" are basically two different terms for the same thing.
    • properties are simply data values that are related to the class. These are values that are intentionally non-isolated to any individual function, because more than one of the functions in the class should have access to them.
      • For example: if your class has a bunch of methods for doing astronomy, properties of the class might be the values for certain famous numbers that all astronomy methods need to know about (like Pi, the speed of light, the distance between specific planets, etc.).
    • This is where most OOP explanations get confusing because they branch off into "real world examples" which can quickly get off-topic. Often, "real world" is a euphemism for the ontological perspectives of a particular individual or group. That tends to be useful only once you already understand the concept well enough to teach it to someone else.
    • To understand OOP without confusion, you can skip the "real world" examples for now, and just focus on the code. A Class is simply a way to store functions (aka methods) and properties (aka data) as PHP code in one or more related "chunks" where each individual "chunk" deals with a specific topic or piece of functionality. That's all you need to know in order to get started.
  • A Class is useful because it allows you to organize your code at a very high level in a way that makes it easy for you to understand, use, and maintain.

  • When someone has written a lot of functions, and organized them into a lot of Classes, and gotten those to work together in some cool way, they package the whole thing together and call it a "Framework".

  • A Framework is just the next-highest level of "chunking" (including coding style and conventions) that one or more people agree on because they like the way the code is organized and it suits their working style, preferences, values, plans for world domination, etc.

See also

  • OOP appeal
Wednesday, March 31, 2021
answered 7 Months ago

The answer to which one is better is "it depends." As with anything, there are a variety of different approaches and you should also keep in mind that code that uses objects is not necessarily object oriented but can still be written procedurally. In the same vein, code that does not use objects can still be modular.

I would choose to use the mysqli class every time, though. There is no significant difference in performance. You probably won't realize some of the advantages of using a DB class such as simplified polymorphism, so my only argument for using the class is that I prefer the syntax. However, rather than use mysqli directly I would probably recommend that you extend or compose it. You can only do this with the class.

class DB extends mysqli {
    public function __construct() {
            $_SERVER['DB_USER'], $_SERVER['DB_PASS']);

This is a very shallow example.

An example of the polymorphism I was talking about above would be something like this:

class User implements DAO {
    private $db;
    public function __construct(DB $db) {
        $this->db = $db;

//Testing code is simplified compared to using it in production
class TestDB extends DB {}
new User(new TestDB);
new User(new DB);

By the way I categorically prefer PDO over mysqli

Wednesday, March 31, 2021
answered 7 Months ago

You can test procedural code with PHPUnit. Unit tests are not tied to object-oriented programming. They test units of code. In OO, a unit of code is a method. In procedural PHP, I guess it's a whole script (file).

While OO code is easier to maintain and to test, that doesn't mean procedural PHP cannot be tested.

Per example, you have this script:


$arg1 = $_GET['arg1'];
$arg2 = $_GET['arg2'];
$return = (int)$arg1 + (int)$arg2;
echo $return;

You could test it like this:

class testSimple_add extends PHPUnit_Framework_TestCase {

    private function _execute(array $params = array()) {
        $_GET = $params;
        include 'simple_add.php';
        return ob_get_clean();

    public function testSomething() {
        $args = array('arg1'=>30, 'arg2'=>12);
        $this->assertEquals(42, $this->_execute($args)); // passes

        $args = array('arg1'=>-30, 'arg2'=>40);
        $this->assertEquals(10, $this->_execute($args)); // passes

        $args = array('arg1'=>-30);
        $this->assertEquals(10, $this->_execute($args)); // fails


For this example, I've declared an _execute method that accepts an array of GET parameters, capture the output and return it, instead of including and capturing over and over. I then compare the output using the regular assertions methods from PHPUnit.

Of course, the third assertion will fail (depends on error_reporting though), because the tested script will give an Undefined index error.

Of course, when testing, you should put error_reporting to E_ALL | E_STRICT.

Saturday, May 29, 2021
answered 5 Months ago

All of them are good in their own ways - They're simply different approaches to the same problems.

In a purely procedural style, data tends to be highly decoupled from the functions that operate on it.

In an object oriented style, data tends to carry with it a collection of functions.

In a functional style, data and functions tend toward having more in common with each other (as in Lisp and Scheme) while offering more flexibility in terms of how functions are actually used. Algorithms tend also to be defined in terms of recursion and composition rather than loops and iteration.

Of course, the language itself only influences which style is preferred. Even in a pure-functional language like Haskell, you can write in a procedural style (though that is highly discouraged), and even in a procedural language like C, you can program in an object-oriented style (such as in the GTK+ and EFL APIs).

To be clear, the "advantage" of each paradigm is simply in the modeling of your algorithms and data structures. If, for example, your algorithm involves lists and trees, a functional algorithm may be the most sensible. Or, if, for example, your data is highly structured, it may make more sense to compose it as objects if that is the native paradigm of your language - or, it could just as easily be written as a functional abstraction of monads, which is the native paradigm of languages like Haskell or ML.

The choice of which you use is simply what makes more sense for your project and the abstractions your language supports.

Wednesday, June 2, 2021
answered 5 Months ago

The difference between the two is subtle but significant.

In a procedural program, modules interact by reading and writing state that is stored in shared data structures.

In an object oriented program, modules in the form of objects interact by sending messages to other objects.

Saturday, August 7, 2021
Do Tog
answered 3 Months ago
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