What do the symbols $ @ and % mean when prefixing a
variable?
what is the function of Return Value?
What is the use of "stderr()"?
What is hash?
Explain the various characteristics of perl.
How do I debug a perl program?
Consider the following example #! /bin/perl use strict; sub sample { my @arr=(1,2,3,4); return @arr; } my ($a,$b,$c,$d) = &sample; print "$a\n$b\n$c\n$d\n"; In the above code, How can I get the $c without using the arguments such as $a,$b. I don't want to use any array to get the return values.
What are the different instances used in cgi overhead?
What is the difference between chop & chomp functions in perl?
10 Answers Cap Gemini, DELL, Electronic Data, TCS,
Explain 'grep' function.
package MYCALC; use Exporter; our @EXPORT = (); our @ISA = qw(Exporter); our @EXPORT_OK = qw(addition multi); our %EXPORT_TAGS = (DEFAULT => [qw(&addition)],Both => [qw(&addition & +multi)]); sub addition { return $_[0] + $_[1]; } sub multi { return $_[0] * $_[1]; } 1; Program: use strict; use warnings; my @list = qw (2 2); use Module qw(:DEFAULT); print addition(@list),"\n"; Above coding is my module MYCALC and the program which using this module, I have not exported any function using @EXPORT, but I have used the DEFAULT in %EXPORT_TAGS with the function addition, when I call this function from the main it says the error as,
Write an example explaining the use of symbol tables.
while (my ($key, $value) = each(%ENV)) { print "$key - $value\n"; } What does the above sample code produce? What function do you use for reading a list of files within a directory? my %hash = ( 'hi' => {'hello' => 'all'}, 'bye' => {'later' => 'gone'} ); print $hash{'hi'}; What is printed when the above code is executed? sub new { my $pkg = shift; my $test = {'name' => shift;}; ???? return $test; } Which one of the following replaces "????" in the above code in order to cause the function new to return an object of type "Test"? while (<STDIN>) { ???? print "$_\n"; } Which one of the following statements causes the above code to strip all whitespace from the end of all lines of input and to print the resulting lines to standard output while (my ($key,$value) = each(%hash)) { print "$key - $value\n"; delete $hash{$key}; } open(FILE,"<file.dat"); my $data = ''; { local $/ = undef; $data = <FILE>; } close(FILE); my $foo = 21; $foo <<= 5; $foo >>= 4; print $foo; @arr = (1,2,3); {local $" = "\n"; print "@arr\n"; } my $line = "Hello World"; substr($line,5,2) = "abc"; print $line; Why is sprintf rarely used in perl in comparison to similar (or the same) functions in other languages? my $subRef = sub {print shift;}; How is the subroutine above called with one parameter? How can the values of an associative array be placed in sorted order in a new array? What function is often necessary for building data structures to be passed to low-level routines such as ioctl and fcntl? sub foo { if (shift(@_) > 0) { shift; } } print foo(10,5); print foo(-10,5); What does the above sample for (my $i = 1; $i <= 3; $i++) { print 1..$i; print "\n"; } my $data = 5**3 * 12,2+2; print $data; sub foo { my $value = shift; if ($value) { print 1; shift; } else { return shift(@_) + 3; } } print foo(10,20); What is printed as the result of executing the above code? $var = 20; sub s1 { print "$var "; } sub s2 { local $var = 10; s1;} sub s3 { my $var = 30; s1;} s3; s2; s1; On systems that record file ownership, how may the owner of a file be identified? Which one of the following sets $y to be a copy of $x with every occurrence of foo changed to bar? Which one of the following is an array literal that represents a 4-element array containing the numbers 1, 4, 2, and 6? sub foo {2*shift || 'x';} printf ("%s %s %s", foo(5),foo(0),foo(-5)); What does the above sample code print? Suppose $x contains a number. Which one of the following statements sets $y to be a string containing the octal value of $x?