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How to create Array in Perl?

Mohd Mohtashim
Updated on 28-Nov-2019 09:34:35

249 Views

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';

Understanding Perl Array

Mohd Mohtashim
Updated on 28-Nov-2019 09:32:06

252 Views

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

Perl Special Literals

Mohd Mohtashim
Updated on 28-Nov-2019 09:30:04

460 Views

Let me tell you about three special literals __FILE__, __LINE__, and __PACKAGE__ represent the current filename, line number, and package name at that point in your program.They may be used only as separate tokens and will not be interpolated into strings. Check the below example −Example Live Demo#!/usr/bin/perl print "File name ". __FILE__ . ""; print "Line Number " . __LINE__ .""; print "Package " . __PACKAGE__ .""; # they can not be interpolated print "__FILE__ __LINE__ __PACKAGE__";OutputThis will produce the following result −File name hello.pl Line Number 4 Package main __FILE__ __LINE__ __PACKAGE__

V-Strings in Perl

Mohd Mohtashim
Updated on 28-Nov-2019 09:27:00

660 Views

A literal of the form v1.20.300.4000 is parsed as a string composed of characters with the specified ordinals. This form is known as v-strings.A v-string provides an alternative and more readable way to construct strings, rather than use the somewhat less readable interpolation form "\x{1}\x{14}\x{12c}\x{fa0}".They are any literal that begins with a v and is followed by one or more dot-separated elements. For example −Example Live Demo#!/usr/bin/perl $smile = v9786; $foo = v102.111.111; $martin = v77.97.114.116.105.110; print "smile = $smile"; print "foo = $foo"; print "martin = $martin";OutputThis will also produce the same result −smile = ☺ foo = foo martin ... Read More

Multiline Strings in Perl

Mohd Mohtashim
Updated on 28-Nov-2019 09:12:15

2K+ Views

If you want to introduce multiline strings into your programs, you can use the standard single quotes as below −Example Live Demo#!/usr/bin/perl $string = 'This is a multiline string'; print "$string";OutputThis will produce the following result −This is a multiline stringYou can use "here" document syntax as well to store or print multiline as below −Example Live Demo#!/usr/bin/perl print

Perl String Scalars

Mohd Mohtashim
Updated on 28-Nov-2019 08:19:14

300 Views

The following example demonstrates the usage of various types of string scalars. Notice the difference between single-quoted strings and double-quoted strings −Example Live Demo#!/usr/bin/perl $var = "This is string scalar!"; $quote = 'I m inside single quote - $var'; $double = "This is inside single quote - $var"; $escape = "This example of escape -\tHello, World!"; print "var = $var"; print "quote = $quote"; print "double = $double"; print "escape = $escape";OutputThis will produce the following result −var = This is string scalar! quote = I m inside single quote - $var double = This is inside single quote - ... Read More

Perl Numeric Scalars

Mohd Mohtashim
Updated on 28-Nov-2019 08:16:38

197 Views

A scalar is most often either a number or a string. Following example demonstrates the usage of various types of numeric scalars −Example Live Demo#!/usr/bin/perl $integer = 200; $negative = -300; $floating = 200.340; $bigfloat = -1.2E-23; # 377 octal, same as 255 decimal $octal = 0377; # FF hex, also 255 decimal $hexa = 0xff; print "integer = $integer"; print "negative = $negative"; print "floating = $floating"; print "bigfloat = $bigfloat"; print "octal = $octal"; print "hexa = $hexa";OutputThis will produce the following result −integer = 200 negative = -300 floating = 200.34 bigfloat = -1.2e-23 octal = 255 hexa = 255

What are Perl Scalars?

Mohd Mohtashim
Updated on 28-Nov-2019 08:13:29

213 Views

A scalar is a single unit of data. That data might be an integer number, floating-point, a character, a string, a paragraph, or an entire web page.Here is a simple example of using scalar variables −Example Live Demo#!/usr/bin/perl $age = 25;                # An integer assignment $name = "John Paul";      # A string $salary = 1445.50;        # A floating point print "Age = $age"; print "Name = $name"; print "Salary = $salary";OutputThis will produce the following result −Age = 25 Name = John Paul Salary = 1445.5

Perl Variable Context

Mohd Mohtashim
Updated on 28-Nov-2019 08:11:25

505 Views

Perl treats the same variable differently based on Context, i.e., the situation where a variable is being used. Let's check the following example −Example Live Demo#!/usr/bin/perl @names = ('John Paul', 'Lisa', 'Kumar'); @copy = @names; $size = @names; print "Given names are : @copy"; print "Number of names are : $size";OutputThis will produce the following result −Given names are : John Paul Lisa Kumar Number of names are : 3Here @names is an array, which has been used in two different contexts. First, we copied it into another array, i.e., list, so it returned all the elements assuming that context ... Read More

Perl Hash Variables

Mohd Mohtashim
Updated on 28-Nov-2019 08:08:19

322 Views

A hash is a set of key/value pairs. Hash variables are preceded by a percent (%) sign. To refer to a single element of a hash, you will use the hash variable name followed by the "key" associated with the value in curly brackets.Here is a simple example of using hash variables −Example Live Demo#!/usr/bin/perl %data = ('John Paul', 45, 'Lisa', 30, 'Kumar', 40); print "\$data{'John Paul'} = $data{'John Paul'}"; print "\$data{'Lisa'} = $data{'Lisa'}"; print "\$data{'Kumar'} = $data{'Kumar'}";OutputThis will produce the following result −$data{'John Paul'} = 45 $data{'Lisa'} = 30 $data{'Kumar'} = 40

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