Option _Explicit Keyword(s) of day XXX:

[TerryRitchie]

I added OPTION _EXPLICIT yesterday to Lesson2: Introducing Variables in the tutorial:

https://www.qb64tutorial.com/lesson2

I used Steve's Cheetos example too

@Terry (and @bplus) a constant is just an ordinary variable that can be accidentally changed without the Option Explicit.

From your tutorial:

Correct. If OPTION _EXPLICIT were the first line of code in the example, the variable mm would have been flagged immediately. Also, a constant is not an ordinary variable. A constant can't have its value changed once set. The IDE will flag this if you try it:

CONST Foo = 10
Foo = 3

"Expected variable = on line 2"

The IDE does not recognize Foo as a variable because it's been declared as a constant.