What's the difference between `if var in` and `if var contains`?

Question

The AutoHotkey documentation lists two methods of comparing a variable to items in a list.

if Var in MatchList
if Var contains MatchList

What's the difference between if var in and if var contains ?

Answer 1

Hopefully some examples will help demonstrate the difference.

Example of if var in MatchList :

Match:

F3::
example := "pizza" ; Contains a matching string.
if example in This,is,a,tasty,pizza
    MsgBox, %example% found in MatchList

Negative match:

F3::
example := "pizz" ; Contains no matching string.
if example not in This,is,a,tasty,pizza
    MsgBox, %example% not found in MatchList

Example of if var contains MatchList :

Match:

F3::
example := "ice" ; Contains a matching "i" substring.
if example contains p,i,z,z,a
    MsgBox, %example% contains MatchList item(s)

Negative match:

F3::
example := "doggy" ; Contains no matching substring.
if example not contains p,i,z,z,a
    MsgBox, %example% does not contain MatchList item(s)