number of digits

num-digits: whole-number -> number

Returns how many digits in the number.

number of digits

• Use conditional.
• Base: answer of 1

number of digits

(define (num-digits n)
  (cond [(< n 10) 1]
        [else ... ]))

number of digits

• Use conditional.
• Base: answer of 1
• Else: one more than …

number of digits

Trick:

• (quotient number 10) has one fewer digit