Default (keyword), Auto conversion.

[anonymous]

Not to sure. But if there test true. (they do)

If (10 + Default) = 9 Then ConsoleWrite("(Default + 10) = 9" & @CRLF)
If ('abc' & Default) = 'ABCDefault' Then ConsoleWrite("(Default & 'abc') = 'DefaultABC'" & @CRLF)

than (I think) these should fail. (they don't)

If 'default' <> Default Then ConsoleWrite("'Default' <> Default" & @CRLF)
If -1 <> Default Then ConsoleWrite(" -1 <> Default" & @CRLF)

Default keyword not auto converted in last cases. (direct_compare)

[anonymous]

No bug as it seems.

Doc: if you try and multiply two variants they will be treated as numbers, if you try and concatenate (join) two variants they will be treated as strings.

Explains the result in the first code.

This keyword(Default) should not be used in a general computation expression. AutoIt will not detect such situations because it has too much of a performance penalty.

Not to sure if this apply's to this situation. (assuming it is)

[Jpm]

is it the same anonymous which give a so clear explanation?

Anyway I think the doc explain what is happening.

[anonymous]

is it the same anonymous which give a so clear explanation?

yes.