转换大写和小写

如前所述，字符串通常不区分大小写，但仅考虑字符串的比较。内置函数可以更换外壳。

CAPS（字符串）

使字符串大写

LC（字符串）

使字符串小写

DEFINE VARIABLE c AS CHARACTER   NO-UNDO.
DEFINE VARIABLE d AS CHARACTER   NO-UNDO.

c = "Hello".
d = "World".

DISPLAY CAPS(c) LC(d). // HELLO world

记住字符串通常不区分大小写

DEFINE VARIABLE c AS CHARACTER   NO-UNDO.
DEFINE VARIABLE d AS CHARACTER   NO-UNDO.

c = "hello".
d = "hello".

DISPLAY CAPS(c) = LC(d). // yes

除非特定为 CASE-SENSITIVE

DEFINE VARIABLE c AS CHARACTER   NO-UNDO CASE-SENSITIVE.
DEFINE VARIABLE d AS CHARACTER   NO-UNDO.

c = "hello".
d = "hello".

DISPLAY CAPS(c) = LC(d). // no