Why does Assigned return true for uninitialized variables?

Question

I read many posts on forum about pointers, Assigned function, Free function, FreeAndNil function, etc... I already know Free function

Answer 1

Your variable is a local variable and so is not initialized. It could contain any value.

The documentation says:

On the Win32 platform, the contents of a local variable are undefined until a value is assigned to them.

Note that, as an implementation detail, some types are managed and even local variables of managed types are initialized. Examples of managed types include: strings, interfaces, dynamic arrays, anonymous types and variants.

You ask:

Is there any safe way to know if a class variable already has its create method executed?

If that variable is a local variable, the answer is no. The onus falls to you the programmer. In practice it is seldom an issue because good code has short procedures which makes it harder for you to slip up. And even if you do the compiler will invariably warn you.

Other types of variables like class fields and global variables are initialized.