Empty string: Difference between revisions

{{trans|Clojure}}

{{trans|Common Lisp}}

{{trans|Erlang}}

<lang lisp>

> (set str "")

()

> (length str)

0

> (=:= 0 (length str))

true

> (=:= 0 (length "apple"))

false

> (=:= "apple" "")

false

> (=/= "apple" "")

true

> (=:= str "")

true

> (=:= "apple" '())

false

> (=/= "apple" '())

true

> (=:= str '())

true

> (case str ('() 'empty) ((cons head tail) 'not-empty))

empty

> (case "apple" ('() 'empty) ((cons head tail) 'not-empty))

not-empty

</lang>