Found 157 Articles for PERL

We can use the join() function in Perl to rejoin the array elements and form one long scalar string. This function has the following syntax −Syntaxjoin EXPR, LISTThis function joins the separate strings of LIST into a single string with fields separated by the value of EXPR and returns the string. Following is the example −Example Live Demo#!/usr/bin/perl # define Strings $var_string = "Rain-Drops-On-Roses-And-Whiskers-On-Kittens"; $var_names = "Larry, David, Roger, Ken, Michael, Tom"; # transform above strings into arrays. @string = split('-', $var_string); @names = split(', ', $var_names); $string1 = join( '-', @string ); $string2 = join( ', ', @names ... Read More

Let's look into a Perl function called split(), which has the following syntax −Syntaxsplit [ PATTERN [ , EXPR [ , LIMIT ] ] ]This function splits a string into an array of strings and returns it. If LIMIT is specified, splits into at most that number of fields. If PATTERN is omitted, splits on whitespace. Following is the example −Example Live Demo#!/usr/bin/perl # define Strings $var_string = "Rain-Drops-On-Roses-And-Whiskers-On-Kittens"; $var_names = "Larry, David, Roger, Ken, Michael, Tom"; # transform above strings into arrays. @string = split('-', $var_string); @names = split(', ', $var_names); print "$string[3]";    # This will print ... Read More

Now we are going to introduce one more function called splice(), which has the following syntax −Syntaxsplice @ARRAY, OFFSET [ , LENGTH [ , LIST ] ]This function will remove the elements of @ARRAY designated by OFFSET and LENGTH, and replaces them with LIST if specified. Finally, it returns the elements removed from the array. Following is the example −Example Live Demo#!/usr/bin/perl @nums = (1..20); print "Before - @nums"; splice(@nums, 5, 5, 21..25); print "After - @nums";OutputThis will produce the following result −Before - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 ... Read More

You can also extract a "slice" from an array - that is, you can select more than one item from an array in order to produce another array.Example Live Demo#!/usr/bin/perl @days = qw/Mon Tue Wed Thu Fri Sat Sun/; @weekdays = @days[3, 4, 5]; print "@weekdays";OutputThis will produce the following result −Thu Fri SatThe specification for a slice must have a list of valid indices, either positive or negative, each separated by a comma. For speed, you can also use the .. range operator −Example Live Demo#!/usr/bin/perl @days = qw/Mon Tue Wed Thu Fri Sat Sun/; @weekdays = @days[3..5]; print "@weekdays";OutputThis will ... Read More

Perl provides a number of useful functions to add and remove elements in an array. You may have a question what is a function? So far you have used the print function to print various values. Similarly, there are various other functions or sometimes called subroutines, which can be used for various other functionalities.Sr.No.Types & Description1push @ARRAY, LISTPushes the values of the list onto the end of the array.2pop @ARRAYPops off and returns the last value of the array.3shift @ARRAYShifts the first value of the array off and returns it, shortening the array by 1 and moving everything down.4unshift @ARRAY, ... Read More

The size of an array in Perl can be determined using the scalar context on the array - the returned value will be the number of elements in the array −@array = (1, 2, 3); print "Size: ", scalar @array, "";The value returned will always be the physical size of the array, not the number of valid elements. You can demonstrate this, and the difference between scalar @array and $#array, using this fragment is as follows −Example Live Demo#!/usr/bin/perl @array = (1, 2, 3); $array[50] = 4; $size = @array; $max_index = $#array; print "Size: $size"; print "Max Index: $max_index";OutputThis ... Read More

Perl offers a shortcut for sequential numbers and letters. Rather than typing out each element when counting to 100 for example, we can do something like as follows −Example Live Demo#!/usr/bin/perl @var_10 = (1..10); @var_20 = (10..20); @var_abc = (a..z); print "@var_10"; # Prints number from 1 to 10 print "@var_20"; # Prints number from 10 to 20 print "@var_abc"; # Prints number from a to zHere double dot (..) is called range operator. This will produce the following result −1 2 3 4 5 6 7 8 9 10 10 11 12 13 14 15 16 17 18 19 20 a b c d e f g h i j k l m n o p q r s t u v w x y z

When accessing individual elements from an array in Perl, you must prefix the variable with a dollar sign ($) and then append the element index within the square brackets after the name of the variable. For example −Example Live Demo#!/usr/bin/perl @days = qw/Mon Tue Wed Thu Fri Sat Sun/; print "$days[0]"; print "$days[1]"; print "$days[2]"; print "$days[6]"; print "$days[-1]"; print "$days[-7]";OutputThis will produce the following result −Mon Tue Wed Sun Sun MonArray indices start from zero, so to access the first element you need to give 0 as indices. You can also give a negative index, in which case you select ... Read More

Perl Array variables are prefixed with the @ sign and are populated using either parentheses or the qw operator. For example −@array = (1, 2, 'Hello'); @array = qw/This is an array/;The second line uses the qw// operator, which returns a list of strings, separating the delimited string by white space. In this example, this leads to a four-element array; the first element is 'this' and last (fourth) is 'array'. This means that you can use different lines as follows −@days = qw/Monday Tuesday ... Sunday/;You can also populate an array by assigning each value individually as follows −$array[0] = 'Monday'; ... $array[6] = 'Sunday';

A Perl array is a variable that stores an ordered list of scalar values. Array variables are preceded by an "at" (@) sign. To refer to a single element of an array, you will use the dollar sign ($) with the variable name followed by the index of the element in square brackets.ExampleHere is a simple example of using the array variables − Live Demo#!/usr/bin/perl @ages = (25, 30, 40); @names = ("John Paul", "Lisa", "Kumar"); print "\$ages[0] = $ages[0]"; print "\$ages[1] = $ages[1]"; print "\$ages[2] = $ages[2]"; print "\$names[0] = $names[0]"; print "\$names[1] = $names[1]"; print "\$names[2] = $names[2]";Here we ... Read More