Editing Do while loop (section)

===Racket===
{{Further|Racket (programming language)}}
In Racket, as in other [[Scheme (programming language)|Scheme]] implementations, a "named-let" is a popular way to implement loops:

<syntaxhighlight lang="racket">
#lang racket
(define counter 5)
(define factorial 1)
(let loop ()
    (set! factorial (* factorial counter))
    (set! counter (sub1 counter))
    (when (> counter 0) (loop)))
(displayln factorial)
</syntaxhighlight>

Compare this with the first example of the [[While loop#Racket|while loop]] example for Racket. Be aware that a named let can also take arguments.

Racket and Scheme also provide a proper do loop.
<syntaxhighlight lang="scheme">
(define (factorial n)
    (do ((counter n (- counter 1))
        (result 1 (* result counter)))
    ((= counter 0) result) ; Stop condition and return value.
    ; The body of the do-loop is empty.
    ))
</syntaxhighlight>