I have the following Perl code:
package CustomerCredit;
#!/usr/local/bin/perl
use 5.010;
use strict;
my $TransRef = @_; # This code comes from a sub within the package.
my ($Loop, $TransArrRef, $TransID);
for ($Loop = 0; $Loop < $$#TransRef; $Loop++)
{
$TransArrRef = $$TransRef[$Loop]; # Gets a ref to an array.
$TransID = $$TransArrRef[0]; # Try to get the first value in the array.
# The above line generates a compile time syntax error.
...
}
$TransRef is a reference to an array of references to arrays. I am trying to process each element in the array pointed to by $TransRef. $TransArrRef should obtain a reference to an array. I want to assign the first value within that array to $TransID. But, this statement generates a compile syntax error.
I must be doing something wrong, but can not figure out what it is. Can anyone help?
The syntax error is coming from $$#TransRef
which should be $#$TransRef
. By misplacing the #
you accidentally commented out the rest of the line leaving:
for ($Loop = 0; $Loop <= $$
{
$TransArrRef = $$TransRef[$Loop];
...
}
$$
is ok under strict
as it gives you the process id leaving the compiler to fail further down.
Also, $#$TransRef
gives you the last element in the array so you'd need <=
rather than just <
. Or use this Perl style loop:
for my $loop (0 .. $#$TransRef) {
$TransID = $TransRef->[$loop]->[0];
# ...
}
my $arrays_ref = [ [1,2], [3,4] ];
for my $array_ref (@$arrays_ref) {
printf "%s\n", $array_ref->[0];
}
You can use foreach
as well:
my @array = ('val1', 'val2', 'val3') ;
my $array_ref = \@array ;
print "array size is $#{$array_ref} \n" ;
foreach $elem (@$array_ref) {
print "$elem \n"
}
Outputs:
array size is 2
val1
val2
val3
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