Example 8: Count Total Digits Of A Number

#!/usr/bin/tclsh

puts "Enter a number: "
gets stdin input

proc count_digit {input} {
	set digit 0
	if {$input == 0} {
		puts "It has 1 digit"
	} else {
		while {$input > 0} {
			set input [ expr $input / 10]
			incr digit 1
		}
		puts "It has $digit digit"
	}
	
}

count_digit $input

Output:

Enter a number:
565
It has 3 digit

Enter a number:
608
It has 3 digit