is this the same ?? (PHP)

Question

i saw php syntax on the inetrnet like this

class foo {
      public static $cont = null;

      if (null == self::$cont){
         //doing something here
  }
}

I am wondering are those code "self::$cont" the same like "$this->cont" like this ??

class foo {
      public static $cont = null;

      if (null == $this->cont){
         //doing something here
  }
}

thanks :)

Answer 1 · 2016-02-28T17:57:48Z

February 28, 2016 5:57pm

Hi there,

In short, nope, this is not the same because your second one is going to give you an error. The reason is due to the static keyword that has been included when declaring the property of the foo class.

In order to make the second example not throw an error, you would be required to remove the static keyword from the class before accessing the property with $this->

Essentially, a static property or method of a class is something you can access without actually creating an instance of a class first. For example, if we had this:

<?php
// This class foo uses a static property called $bar.
class foo{
   public static $bar = 'I am a static property!';
}

//To output $bar to the screen, we don't have to create an instance of the class first.
echo foo::$bar;
?>

Now let's look at how we would access $bar by removing the static keyword.

<?php
// This class foo uses a public property called $bar, but this time it's not static.
class foo{
   public $bar = 'I am NOT a static property!';
}

//To output $bar to the screen, we have to create an instance of the foo class first before we access the bar property.
$foo = new foo();

echo $foo->bar;
?>

I hope this helps, getting to grips with the public, static, private and protected terminology for OOP can take some accustoming to, but keep at it and you'll be away in no time! :)

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Rifqi Fahmi

Rifqi Fahmi

is this the same ?? (PHP)

1 Answer

Maximillian Fox

Maximillian Fox

Rifqi Fahmi

Rifqi Fahmi