Server Side Programming Articles - Page 2072 of 2650

Perl Hashes are created in one of the two following ways. In the first method, you assign a value to a named key on a one-by-one basis −$data{'John Paul'} = 45; $data{'Lisa'} = 30; $data{'Kumar'} = 40;In the second case, you use a list, which is converted by taking individual pairs from the list: the first element of the pair is used as the key, and the second, as the value. For example −%data = ('John Paul', 45, 'Lisa', 30, 'Kumar', 40);For clarity, you can use => as an alias for, to indicate the key/value pairs as follows −%data = ... Read More

The list notation in Perl is identical to that for arrays. You can extract an element from an array by appending square brackets to the list and giving one or more indices −Example Live Demo#!/usr/bin/perl $var = (5,4,3,2,1)[4]; print "value of var = $var"OutputThis will produce the following result −value of var = 1Similarly, we can extract slices, although without the requirement for a leading @ character −Example Live Demo#!/usr/bin/perl @list = (5,4,3,2,1)[1..3]; print "Value of list = @list";OutputThis will produce the following result −Value of list = 4 3 2

Because an array in Perl is just a comma-separated sequence of values, you can combine them together as shown below −Example Live Demo#!/usr/bin/perl @numbers = (1,3,(4,5,6)); print "numbers = @numbers";OutputThis will produce the following result −numbers = 1 3 4 5 6The embedded arrays just become a part of the main array as shown below −Example Live Demo#!/usr/bin/perl @odd = (1,3,5); @even = (2, 4, 6); @numbers = (@odd, @even); print "numbers = @numbers";OutputThis will produce the following result −numbers = 1 3 5 2 4 6

Perl provides numerous special variables, which have their predefined meaning.We have a special variable, which is written as $[. This special variable is a scalar containing the first index of all arrays. Because Perl arrays have zero-based indexing, $[ will almost always be 0. But if you set $[ to 1 then all your arrays will use on-based indexing. It is recommended not to use any other indexing other than zero. However, let's take one example to show the usage of $[ variable −Example Live Demo#!/usr/bin/perl # define an array @foods = qw(pizza steak chicken burgers); print "Foods: @foods"; # Let's ... Read More

The sort() function in Perl sorts each element of an array according to the ASCII Numeric standards. This function has the following syntax −Syntaxsort [ SUBROUTINE ] LISTThis function sorts the LIST and returns the sorted array value. If SUBROUTINE is specified then specified logic inside the SUBROUTINE is applied while sorting the elements.Example Live Demo#!/usr/bin/perl # define an array @foods = qw(pizza steak chicken burgers); print "Before: @foods"; # sort this array @foods = sort(@foods); print "After: @foods";OutputThis will produce the following result −Before: pizza steak chicken burgers After: burgers chicken pizza steakPlease note that sorting is performed based on ... Read More

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

PythonPython is a high level programming language with inbuilt big library and is used to develop standalone programs. It was developed by Guido Van Rossum and its first version was released in the year 1990.PHPPHP stands for Hypertext Preprocessor, it is server side scripting language. It was developed in 1995. It is used to create dynamic web based pages.Following are the important differences between Python and PHP.Sr. No.KeyPythonPHP1Learning CurvePython requires good effort if one learns from scratch. It is similar to C++ and Java.PHP is easy to learn if user knows html and javascript.2FrameworksPopular Python frameworks are Flask, DJango.Popular PHP ... Read More

GoGo is a procedural programming language. Programs are assembled using packages. It supports environment adopting patterns similar to dynamic languages.C++C++ is an object oriented programming language. C++ is quiet fast, reliable and secure. It is most widely used language as well.Following are the important differences between Go and C++.Sr. No.KeyGoC++1TypeGo is a procedural programming language and supports patterns similar to dynamic languages.C++ is an object oriented programming language.2Supports for ClassGo has no support for class with constructors.C++ has support for class with constructors.3Garbage CollectionGo has automatic garbage collection.C++ has not provided automatic garbage collection.4InheritanceGo has no support for inheritance.C++ supports ... Read More