Using $this in POO PHP

Question

I don’t quite understand what $this "gets".

In this case we have a code like this, for example:

<?php
class Teste {
    public $testando;
    public function VamosTestar(){
       this->$testando = false; 
   }
}

In the case there, $this is "replacing" what? The test class? If I do so, it will be the same thing?

<?php
    class Teste {
        public $testando;
        public function VamosTestar(){
           Teste->testando = false; 
       }
    }

In this case, I don’t think so, you put an error in my Netbeans IDE. But what I would use if I didn’t want to use $this?

Answer 1

Utilize $this to refer to the object itself. Another option would be self, but this makes reference to the class itself. Simply put, the $this->variavel is for non-static methods, the self::variavel is for static members.

An example of $this and self use.

class Foo {
    // Variável privada
    private $bar = 1;

    // Variável estática
    private static $fooBar = 2;

    function __construct() {
        // Imprime ambas variáveis
        echo $this->bar . ' ' . self::$fooBar;
    }

    // Caso tente imprimir $bar com self, receberá uma mensagem de erro
    // Caso tente imprimir $fooBar com this, receberá uma mensagem de erro
}

Answer 2

Basically the this refers to the class itself.

Understand it this way:

class Teste {
    public $testando;
    public function VamosTestar(){
       $this->testando = false; 
       //estaClasse->testando ou Teste->testando
   }
}

$this: "This class"

testando attribute with name testing.

To access functions of the class itself or attributes of the class itself we use the word reset $this, the $this can also be used to access functions and attributes inherited from another class as in the example below:

class Pai {
    public $nome;
}

class Filho extends Pai {
    public function foo(){
        return $this->nome;
    }
}

Utilizing:

$filho = new Filho();
$filho->foo();

the $this search for the attribute $nome from the first class extended to the current class.;