Example 5: Reverse The Digits Of A Number

#!/usr/bin/tclsh

puts "Enter a number: "
gets stdin number
scan $number %d number

proc reverse_number {in} {
	set num 0
	while {$in > 0} {
		set num [expr ($num * 10) + ($in % 10)]
		set in [ expr $in/10 ]	
	}
	puts "Reverse number: $num"
}

reverse_number $number

Output:

Enter a number:
3452
Reverse number:2543

Enter a number:
1765
Reverse number: 5671