Conflicting statement

[alpinistbg]

Here, at the end of line 943:

... This dirty trick works only in non-virtual methods (that don't call any virtual methods and don't access any fields).

But actually TObject.Free calls TObject.Destroy which is in turn virtual.

[michaliskambi]

Thank you!

Indeed the clause "(that don't call any virtual methods and don't access any fields)" was confusing. It was meant to mean "you cannot call any virtual methods / access fields if Self is (possibly) nil".

I improved the text, also added an example showing it in https://github.com/michaliskambi/modern-pascal-introduction/blob/master/code-samples/method_with_self_nil.lpr . As expected, it works with non-virtual method, but crashes with virtual.