CODEWITHSUNDEEP
perl
Jassi
Jassi

Reputation: 541

Why index function in Perl is behaving strangely here

Here is the sample code:

my $test = "Mike Xavier Smith/123-45-1111/student";
my $name = substr( $test, 0, index($test, "/") );
my $ssn = substr( $test,index($test,"/"));
my $type = substr( $test,index($test, "/", 2) );
print "$name, $ssn, $type \n";
exit;

Output: Mike Xavier Smith, /123-45-1111/student, /123-45-1111/student

This line substr( $test,index($test, "/", 2) ); #offset should be from second occurrence of "/" which means it should print /student.
But why it is printing from first occurrence of "/"?

Upvotes: 1

Views: 133

Answers (1)

ikegami
ikegami

Reputation: 385917

That's not what the third argument of index is at all.

my $test = "Mike Xavier Smith/123-45-1111/student";

my $start = 0;
my $end   = index($test, "/", $start);
my $name  = substr($test, $start, $end);

$start  = $end+1;
$end    = index($test, "/", $start);
my $ssn = substr($test, $start, $end);

$start  = $end+1;
$end    = index($test, "/", $start);
my $type = substr($test, $start, $end);

print "$name, $ssn, $type\n";

Most people would just use split.

my $test = "Mike Xavier Smith/123-45-1111/student";
my ($name, $ssn, $type) = split(qr{/}, $test);
print "$name, $ssn, $type\n";

Upvotes: 8

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