Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
Articles by Mohd Mohtashim
Page 4 of 19
"Here" Documents in Perl
You can store or print multiline text with great comfort. Even you can make use of variables inside the "here" document. Below is a simple syntax, check carefully there must be no space between the
Read MoreEscaping Characters in Perl
Perl uses the backslash (\) character to escape any type of character that might interfere with our code. Let's take one example where we want to print double quote and $ sign −Example#!/usr/bin/perl $result = "This is "number""; print "$result"; print "\$result";OutputThis will produce the following result −This is "number" $result
Read MoreWhat are Perl String Literals?
Strings are sequences of characters. They are usually alphanumeric values delimited by either single (') or double (") quotes. They work much like UNIX shell quotes where you can use single-quoted strings and double-quoted strings.Double-quoted string literals allow variable interpolation, and single-quoted strings are not. There are certain characters when they are proceeded by a backslash, have special meaning and they are used to represent like newline () or tab (\t).You can embed newlines or any of the following Escape sequences directly in your double-quoted strings −Escape sequenceMeaning\Backslash'Single quote"Double quote\aAlert or bell\bBackspace\fForm feedNewline\rCarriage return\tHorizontal tab\vVertical tab\0nnCreates Octal formatted numbers\xnnCreates Hexideciamal ...
Read MorePerl Scalar Variables
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. Simply saying it could be anything, but only a single thing.Here is a simple example of using scalar variables −Example#!/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 = $salary";OutputThis will produce the following result −Age = 25 Name = John Paul Salary = 1445.5
Read MorePerl Array Variables
An array is a variable that stores an ordered list of scalar values. Array variables are preceded by an "at" (@) sign. To refer to a single element of an array, you will use the dollar sign ($) with the variable name followed by the index of the element in square brackets.Here is a simple example of using array variables −Example#!/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 used escape sign ...
Read MorePerl Hash Variables
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#!/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
Read MorePerl Variable Context
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#!/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 is ...
Read MorePerl Numeric Scalars
A scalar is most often either a number or a string. Following example demonstrates the usage of various types of numeric scalars −Example#!/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
Read MorePerl String Scalars
The following example demonstrates the usage of various types of string scalars. Notice the difference between single-quoted strings and double-quoted strings −Example#!/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 - This ...
Read MoreMultiline Strings in Perl
If you want to introduce multiline strings into your programs, you can use the standard single quotes as below −Example#!/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#!/usr/bin/perl print
Read More