(strcase string [flag])


Convert this string to all upper- or all lower-case.


This function converts text in a string to all upper-case or all lower-case (when flag is non-nil).

The case to be converted is specified by the flag argument. When omitted or set to nil, all characters are converted to upper-case. When not nil (T is typically used), all alphabetic characters are converted to lower-case.

Examples

Code Returns
(strcase "Yes") YES
(strcase "NO" T) "no"
(setq var (strcase var)) Permanently changes variable.
(if (= (strcase var) "YES") (...) Temporarily checks variable.

NOTE LISP functions that check and compare text tend to be case-sensitive. For example, (if (= "Y" ans) ...) only works with a capital "Y"; a lowercase "y" is not considered the same. For this reason, it is useful to apply the strcase function to the user's response, as follows:

(setq ans (getchar))

(setq ans (strcase ans))

(if (= "Y" ans)

     ...

)

Tell me about...

(atof string)

(atoi string)

LISP Compatibility

Programming Overview of LISP (LISt Processing) Language