why the 2nd program doesn't work?

rockmountain has asked for the wisdom of the Perl Monks concerning the following question:

The Perfectly running program

#!/usr/bin/perl
# Palindrome.pl
$x=<STDIN>;
chomp($x);
$y=reverse($x);
if($x eq $y)
{
  print "Palindrome";
}
[download]

Second program which doesn't execute

#!/usr/bin/perl
# Palindrome.pl

if((chomp($x=<STDIN>)) eq ($y=reverse($x)))
{
  print "Palindrome";
}#not showing appropriate result. also I am not able watch the express
+ion $x and $y in debug mode.
[download]

cheers Rock

Comment on why the 2nd program doesn't work? Select or Download Code

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Re: why the 2nd program doesn't work? by matija (Priest) on Apr 20, 2004 at 12:16 UTC
Because `chomp $x` returns the number of characters removed from $x - and that is rarely a palindrom of the string contained in $x...	[reply] [d/l]
Re: Re: why the 2nd program doesn't work? by rockmountain (Sexton) on Apr 21, 2004 at 05:00 UTC
So what do you say. There is a error in syntax. I mean I am clueless about it. My C function funda says, it should work. Thanx for reply. cheers Rock	[reply]
Re: Re: Re: why the 2nd program doesn't work? by matija (Priest) on Apr 21, 2004 at 05:45 UTC
No, it is an error in thinking. You are comparing `chomp($x=<STDIN>)` [download] with `$y=reverse($x)` [download] The value of `chomp` is most probably "1" or "2". The value of `$y` is the reverse of `$x` Your "C function funda" most certainly doesn't say that the return of $chomp function must be equal to it's argument. Hint:You can get information on perlfunctions by reading `perldoc perlfunc`, or if you're looking for a specific function, by doing `perldoc -f functionname`	[reply] [d/l] [select]
Re: why the 2nd program doesn't work? by perlinux (Deacon) on Apr 20, 2004 at 12:32 UTC
Try: `... print chomp($x=<STDIN>); ...` [download] it returns 1 ! From "Programming Perl": Unlike chop, chomp returns the number of characters deleted.	[reply] [d/l]