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PERL : check + or - sign in a variable

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# 1  
Old 11-07-2011
PERL : check + or - sign in a variable
I have a variable $max = -3;
It can be $max = +3;

I need to check if this variable is a positive/negative value.
if its positive, should print "positive" if not "negative"

How can this be done?
Thanks in advance
# 2  
Old 11-07-2011
PERL
Hi,

Just check wheather the variable have value greater than or equal to zero then its positive else negative.
Code:
if ( $max >= 0 )
{
   print "Positive\n";
}
else
{
  print "Negative\n";
}

Note: Above works when the variable is integer scalar variable.

if it is string scalar variable, use regex.

Code:
if ( $max =~/^\+/ )
{
   print "Positive\n"
}
elsif ( $max =~/^\-/ )
{
  print "Negative\n";
}
else
{
   print "Positive\n";
}

This User Gave Thanks to rangarasan For This Post:
irudayaraj
# 3  
Old 11-07-2011
Quote:
Originally Posted by rangarasan
...
if it is string scalar variable, use regex.
...
Looks like the integer test works with strings as well.

Code:
$
$ perl -le '$x = "0"; if ($x >= 0) {print "positive"} else {print "negative"}'
positive
$
$ perl -le '$x = "1"; if ($x >= 0) {print "positive"} else {print "negative"}'
positive
$
$ perl -le '$x = "9"; if ($x >= 0) {print "positive"} else {print "negative"}'
positive
$
$ perl -le '$x = "+9"; if ($x >= 0) {print "positive"} else {print "negative"}'
positive
$
$ perl -le '$x = "+0.99"; if ($x >= 0) {print "positive"} else {print "negative"}'
positive
$
$ perl -le '$x = "-0.99"; if ($x >= 0) {print "positive"} else {print "negative"}'
negative
$
$ perl -le '$x = "-1"; if ($x >= 0) {print "positive"} else {print "negative"}'
negative
$
$

tyler_durden
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