Using :: for non static methods?

Question

In the PHP manual it states that the Scope Resolution Operator(::) has the following purpose

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.

Now I just came across a tutorial that was using the double colon like this:

class A {
  public function nice(){
    echo "hi";
  }
}

$A = new A;
A::nice();

and the output is actually

hi

But why does this not throw an error? The function nice is not a static method, nor is one overriding the method. Is it bad practice to use the double colon like that?

That's because you haven't enabled error reporting ([demo](https://3v4l.org/5DVZI)). There's a lot of junk learning material I'm afraid. — Álvaro González, Jan 24 '17 at 15:43
Reaction depends also on PHP Version in PHP70 its this : `Deprecated: Non-static method foo::bar() should not be called statically in ` — JustOnUnderMillions, Jan 24 '17 at 15:46
@ÁlvaroGonzález I actually found that in the book PHP Master from sitepoint. — Adam, Jan 24 '17 at 15:59

Arman P. · Answer 1 · 2017-01-24T15:50:01.920

3

It works for backwards compatibility with PHP 4, if your error reporting is on you will get warning:

Strict Standards: Non-static method A::nice() should not be called statically

EDIT Actually you will get error in recent versions, not warning.

edited Jan 24 '17 at 15:50

answered Jan 24 '17 at 15:44

Arman P.

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http://stackoverflow.com/questions/4684454/error-message-strict-standards-non-static-method-should-not-be-called-staticall – TecBrat Jan 24 '17 at 15:45

score 1 · Answer 2 · answered Jan 24 '17 at 15:50

It actually returns Deprecation notice and it's a bad practice:

PHP Deprecated: Non-static method A::nice() should not be called statically

It does not throw an error, because it's not referencing $this, so this method could be static anyway.

If you would try to reference $this, you will get following error:

Fatal error: Uncaught Error: Using $this when not in object context

Using :: for non static methods?

2 Answers2