type: function (subr) location: built-in source file: xlstr.c Common LISP compatible: yes supported on: all machines
(char/= <char1> <charN> ... ) <char1> - a character expression <charN> - character expression(s) to compare
The CHAR/= (character-NOT-EQUAL) function takes one or more character arguments. It checks to see if all the character arguments are different values. T is returned if the arguments are of different ASCII value. In the case of two arguments, this has the effect of testing if <char1> is not equal to <char2>. This test is case sensitive - the character #\a is different (and of greater ASCII value) than #\A.
(char/= #\a #\b) ; returns T (char/= #\a #\b #\c) ; returns T (char/= #\a #\a) ; returns NIL (char/= #\a #\b #\b) ; returns NIL (char/= #\A #\a) ; returns T (char/= #\a #\A) ; returns T
NOTE: Be sure that the CHAR/= function is properly typed in. The '/' is a forward slash. It is possible to mistakenly type a '\' (backslash). This is especially easy because the character mechanism is '#\a'. If you do use the backslash, no error will be reported because backslash is the single escape character and the LISP reader will evaluate 'CHAR\=' as 'CHAR='. No error will be reported, but the sense of the test is reversed.