theachoem
commented
3 years ago 2. OOP
class Fruit {
// Properties
public $name;
// Method
function set_name($name) {
$this->name = $name;
}
}
$banana = new Fruit();
$apple->set_name('Apple');You can use the instanceof keyword to check if an object belongs to a specific class:
<?php $apple = new Fruit(); var_dump($apple instanceof Fruit); //result: bool(true) ?>
I. Constructor
function __construct($name) {
$this->name = $name;
}II. Destructor
function __destruct() {
echo "The fruit is {$this->name}.";
}III. Access modifiers
There are three access modifiers:
1. public - the property or method can be accessed from everywhere. This is default
2. protected - the property or method can be accessed within the class and by classes derived from that class
3. private - the property or method can ONLY be accessed within the classIV. Inheritent
class Strawberry extends Fruit {
//statement
}V. Constant
class Goodbye {
const LEAVING_MESSAGE = "Thank you for visiting W3Schools.com!";
}
echo Goodbye::LEAVING_MESSAGE;we can access a constant from inside the class by using the self keyword.
class Goodbye {
const LEAVING_MESSAGE = "Thank you for visiting W3Schools.com!";
public function byebye() {
echo self::LEAVING_MESSAGE;
}
}
$goodbye = new Goodbye();
$goodbye->byebye();VI. Abstract class
// Parent class
abstract class Car {
public $name;
public function __construct($name) {
$this->name = $name;
}
abstract public function intro() : string;
}VII. Child classes
class Audi extends Car {
public function intro() : string {
return "Choose German quality! I'm an $this->name!";
}
}VIII. Interface
interface Animal {
public function makeSound();
}
class Cat implements Animal {
public function makeSound() {
echo "Meow";
}
}
$animal = new Cat();
$animal->makeSound();Interface are similar to abstract classes. The difference between interfaces and abstract classes are:
- Interfaces cannot have properties, while abstract classes can
- All interface methods must be public, while abstract class methods is public or protected
- All methods in an interface are abstract, so they cannot be implemented in code and the abstract keyword is not necessary
- Classes can implement an interface while inheriting from another class at the same timeIX. Trait
- Reference: https://www.w3schools.com/php/php_oop_traits.asp
X. Static method
Static methods can be called directly - without creating an instance of the class first.
ClassName::staticMethod();XI. Static properties
Static properties can be called directly - without creating an instance of a class.
ClassName::staticProp;XII. Namespace
Namespaces are qualifiers that solve two different problems: - They allow for better organization by grouping classes that work together to perform a task
- They allow the same name to be used for more than one class
```php namespace Html; class Table { public $title = ""; public $numRows = 0; public function message() { echo "<p>Table '{$this->title}' has {$this->numRows} rows.</p>"; } }
//usage $table = new Html\Table() //or use Html as H; $table = new H\Table() //or use Html\Table as T; $table = new T();
- [Iterable](https://www.w3schools.com/php/php_iterables.asp)
1. Normal PHP
Comment in PHP:
I. Array
Reference: https://www.php.net/manual/en/language.types.array.php
Indexed arrays
Associative arrays
Or
Two-dimensional Arrays
Sorting
sort() - sort arrays in ascending order
rsort() - sort arrays in descending order
asort() - sort associative arrays in ascending order, according to the value
ksort() - sort associative arrays in ascending order, according to the key
arsort() - sort associative arrays in descending order, according to the value
krsort() - sort associative arrays in descending order, according to the key
Operators are used to perform operations on variables and values. PHP divides the operators in the following groups:
Arithmetic operators
Assignment operators
Comparison operators
Increment/Decrement operators
Logical operators
String operators
Array operators
Conditional assignment operators
For loop
There are 2 types of foreach.