$input =~ /[0-9]/; #### $input =~ /\d/; #### 21 dfjdfkfjd2 jf2kjf 9343kfd2 #### $input =~ /^\D*\d\D*$/; #### $input =~ /^\d$/
## $input =~ /\d/; ##
## 21 dfjdfkfjd2 jf2kjf 9343kfd2 ##
## $input =~ /^\D*\d\D*$/; ##
## $input =~ /^\d$/