Perl, using variable from within While loop outside of the loop?
This seems really simple but it is giving me a hard time figuring it out as I'm new to perl.. I've been looking through a lot of documentation now about loops and I am still stumped by this... I have a sub that contains a while loop and I want to use a variable value from within the loop outside of the loop (after the loop has run), however when I try to print out the variable, or return it out of the sub, it doesn't work, only when I print the variable from within the loop does it work.. I would appreciate any advice as to what I'm doing wrong.
Doesn't work (doesn't print $test ):
sub testthis {
$i = 1;
while ($i <= 2) {
my $test = 'its w开发者_JS百科orking' ;
$i++ ;
}
print $test ;
}
&testthis ;
Works, prints $test:
sub testthis {
$i = 1;
while ($i <= 2) {
my $test = 'its working' ;
$i++ ;
print $test ;
}
}
&testthis ;
You declare variable test inside the loop, so it scope is the loop, as soon as you leave the loop the variable is not longer declared.
Add my $test;
just between $i=1
and while(..)
and it will work. The scope will now be the entire sub instead of only the loop
Place my $test
before the while loop. Note that it will only contain the last value that is assigned in the while loop. Is that what you are after?
// will print "it's working" when 'the loop is hit at least once,
// otherwise it'll print "it's not working"
sub testthis {
$i = 1;
my $test = "it's not working";
while ($i <= 2) {
$test = "it's working";
$i++ ;
}
print $test ;
}
you can try this one:
sub testthis {
my $test
$i = 1;
while ($i <= 2) {
$test = 'its working' ;
$i++ ;
print $test ;
}
}
&testthis ;
Note: whenever write perl code, its better to add use strict;
and use warning
in the beginning of the code.
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