All strings in Progress ABL are case sensitive unless specified otherwise.
This example will display a message box saying that the strings are identical.
DEFINE VARIABLE str1 AS CHARACTER NO-UNDO.
DEFINE VARIABLE str2 AS CHARACTER NO-UNDO.
str1 = "abc".
str2 = "ABC".
IF str1 = str2 THEN
MESSAGE "The strings are identical" VIEW-AS ALERT-BOX.
To declare a string case sensitive you just add the attribute CASE-SENSITIVE
DEFINE VARIABLE str1 AS CHARACTER NO-UNDO CASE-SENSITIVE.
DEFINE VARIABLE str2 AS CHARACTER NO-UNDO.
str1 = "abc".
str2 = "ABC".
IF str1 = str2 THEN
MESSAGE "The strings are identical" VIEW-AS ALERT-BOX.
ELSE
MESSAGE "There's a difference" VIEW-AS ALERT-BOX.
(It's enough that one of the strings has it in this case).