What is difference between self and this in PHP?

PHP self refers to the class members, but not for any particular object. This is because the static members(variables or functions) are class members shared by all the objecxts of the class. Whereas, $this wil refer the member variables and function for a particular instance.

What does the :: mean in PHP?

The Scope Resolution Operator (also called Paamayim Nekudotayim) or in simpler terms, the double colon, is a token that allows access to static, constant, and overridden properties or methods of a class. It’s possible to reference the class using a variable.

What is the difference between using self and this?

self is used to access static or class variables or methods and this is used to access non-static or object variables or methods. So use self when there is a need to access something which belongs to a class and use $this when there is a need to access a property belonging to the object of the class.

How does this work in PHP?

$this is a reserved keyword in PHP that refers to the calling object. It is usually the object to which the method belongs, but possibly another object if the method is called statically from the context of a secondary object. This is because in PHP $this is treated as a pseudo-variable.

What does arrow mean in PHP?

Short closures, also called arrow functions, are a way of writing shorter functions in PHP. This notation is useful when passing closures to functions like array_map or array_filter . This is what they look like: // A collection of Post objects $posts = [/* …

What does a $$$ mean in PHP?

PHP $ and $$ Variables. The $var (single dollar) is a normal variable with the name var that stores any value like string, integer, float, etc. The $$var (double dollar) is a reference variable that stores the value of the $variable inside it. To understand the difference better, let’s see some examples.

What does this refer to in OOP?

In many object-oriented programming languages, this (also called self or Me ) is a variable that is used in instance methods to refer to the object on which they are working. The first OO language, SIMULA 67, used this to explicitly reference the local object.

What is this function in JavaScript?

The JavaScript this keyword refers to the object it belongs to. It has different values depending on where it is used: In a method, this refers to the owner object. Alone, this refers to the global object. In a function, this refers to the global object.

What is callback function PHP?

A callback function (often referred to as just “callback”) is a function which is passed as an argument into another function. Any existing function can be used as a callback function.

What is a closure PHP?

Basically a closure in PHP is a function that can be created without a specified name – an anonymous function. By specifying the $v parameter as a reference one can modify each value in the original array through the closure function.

What are the data types used in PHP?

PHP supports the following data types:

• String.
• Integer.
• Float (floating point numbers – also called double)
• Boolean.
• Array.
• Object.
• NULL.
• Resource.