Found 157 Articles for PERL

Perl variables do not have to be explicitly declared to reserve memory space. The declaration happens automatically when you assign a value to a variable. The equal sign (=) is used to assign values to variables.Keep a note that this is mandatory to declare a variable before we use it if we use strict statement in our program.The operand to the left of the = operator is the name of the variable, and the operand to the right of the = operator is the value stored in the variable. For example −$age = 25;             ... Read More

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 More

Perl stores all the numbers internally as either signed integers or double-precision floating-point values. Numeric literals are specified in any of the following floating-point or integer formats −TypeValueInteger1234Negative integer-100Floating point2000Scientific notation16.12E14Hexadecimal0xffffOctal0577

Perl is a loosely typed language and there is no need to specify a type for your data while using it in your program. The Perl interpreter will choose the type based on the context of the data itself.Perl has three basic data types: scalars, arrays of scalars, and hashes of scalars, also known as associative arrays. Here is a little detail about these data types.Sr.No.Types & Description1ScalarScalars are simple variables. They are preceded by a dollar sign ($). A scalar is either a number, a string, or a reference. A reference is actually an address of a variable, which ... Read More

Perl borrows syntax and concepts from many languages: awk, sed, C, Bourne Shell, Smalltalk, Lisp, and even English. However, there are some definite differences between the languages. This chapter is designed to quickly get you up to speed on the syntax that is expected in Perl.A Perl program consists of a sequence of declarations and statements, which run from the top to the bottom. Loops, subroutines, and other control structures allow you to jump around within the code. Every simple statement must end with a semicolon (;).A Perl identifier is a name used to identify a variable, function, class, module, ... Read More

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 Live Demo#!/usr/bin/perl $result = "This is \"number\""; print "$result"; print "\$result";OutputThis will produce the following result −This is "number" $result

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

You can use double quotes or single quotes around literal strings as follows −Example Live Demo#!/usr/bin/perl print "Hello, world"; print 'Hello, world';OutputThis will produce the following result −Hello, world Hello, world$There is an important difference between single and double-quotes. Only double quotes interpolate variables and special characters such as newlines , whereas a single quote does not interpolate any variable or special character. Check below example where we are using $a as a variable to store a value and later printing that value −Example Live Demo#!/usr/bin/perl $a = 10; print "Value of a = $a"; print 'Value of a = $a';OutputThis will ... Read More

A Perl program does not care about whitespaces. Following program works perfectly fine −#!/usr/bin/perl print    "Hello, world";But if spaces are inside the quoted strings, then they would be printed as is. For example −Example Live Demo#!/usr/bin/perl # This would print with a line break in the middle print "Hello          world";OutputThis will produce the following result −Hello       worldAll types of whitespace like spaces, tabs, newlines, etc. are equivalent to the interpreter when they are used outside of the quotes. A line containing only whitespace, possibly with a comment, is known as a blank line, ... Read More

Comments in any programming language are friends of developers. Comments can be used to make program user-friendly and they are simply skipped by the interpreter without impacting the core functionality. For example, in the above program, a line starting with hash # is a comment.Simply saying comments in Perl start with a hash symbol and run to the end of the line −# This is a comment in perlLines starting with = are interpreted as the start of a section of embedded documentation (pod), and all subsequent lines until the next =cut are ignored by the compiler. Following is the ... Read More