CareerCup

Your answer seems incorrect, it checks for only 1 digit from 0-9 range. Instead it should be some thing like [1-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]. Can suggest a better way to write this expression in perl?

Hi Killer. You were right. Here is my example and output

#! /usr/bin/perl

print "Enter a 9 digit number: ";
$number = <>;
chomp $number;

if ($number =~ /\d{9}/) {
print "$number is a 9 digit number\n";
}
else {
print "$number is not a 9 digit number\n";
}


Output & Test Case
-------------------

bash-2.05$ perl match.pl
Enter a 9 digit number: 234567890
234567890 is a 9 digit number

bash-2.05$ perl match.pl
Enter a 9 digit number: 12345
12345 is not a 9 digit number

bash-2.05$ perl match.pl
Enter a 9 digit number: a1234
a1234 is not a 9 digit number

bash-2.05$ perl match.pl
Enter a 9 digit number: a12345678
a12345678 is not a 9 digit number

@Metallicatony

So did you give a wrong answer in the interview? And did you make it to the next round? I am worried because I did something similar and I am waiting for their call.

The answer would be [0-9]{9}. This looks for a number having exactly nine repetitions.

But this wouldn't give numbers having exactly 9 digits i guess? it would give numbers/strings having 9digits or more.
For e.g 989842342342342897 would also be eligible, and it's not a 9 digit nubmer.
The correct code would be i guess, [^0-9][0-9]\{9\}[^0-9] if you were looking for exactly some nine digit number.

$number=~ /[0-9]{9}/

All the above solutions wont give exactly 9 digits. Try this. /^\d{9}$/

Complete Code:

#! /usr/bin/perl

print "Enter a 9 digit number: ";
$number = <>;
chomp $number;

if ($number=~ /^\d{9}$/) {
print "$number is a 9 digit number\n";
}
else {
print "$number is not a 9 digit number\n";
}