Perl join FunctionNEW!!! Check my new resource: Perl How To Tutorial eBooks The syntax form of Perl join function is as follows: As you can see, the join function has two parameters:
Perl join function is the opposite of the Perl split function: meanwhile join function concatenates the elements of a list into a string, split function breaks up a string into a list of words and returns that list. Next, a simple example about how to use it: If you run it, you’ll get as output: In the above example we used the space separator to glue the elements of the @perlFunc array. As you see, you can omit the parentheses when you call the Perl join function. You can concatenate two or more strings, using the dot (.) operator. The main difference between the dot operator and the join function is that whether the dot operator has two operands (the strings that will be merged), Perl join function can use a separator and is called against the elements of a list or array. You can rewrite the above example using the dot operator: The output will be the same as before. I’ll show you now two other snippet code examples with the join function. Check my new How To Tutorial eBooks (PDF format): to see a lot of fully commented examples that help you use the Perl statements and the Perl buit-in functions in your scripts.
As you have noticed in the example above, you can use a string as a separator ("--") in order to join the elements of an array into a string. We used the split function to split the string into an array.
First, I want to remind you the @ARGV array, in a few words. This is a special array of Perl and is the list of arguments passed to a script that you run from a command line. In a command line the arguments are separated by space. $ARGV[0] will store the first argument, $ARGV[1] the second argument and so on. If you want to find the number of the command-line arguments, you can invoke the size of the @ARGV array, i.e. $#ARGV+1 (you need to add 1 because $#ARGV actually represents the last subscript of the array, the first subscript being 0). If you want, you can run the Perl script without arguments in the command line and initialize the @ARGV array across your Perl script. In the following example we want to concatenate the command-line arguments into a string using the join function – the arguments will be separated by '|' delimiter. Our example is meant to be run on a Windows machine. We’ll analyze the case when the arguments can contain spaces. See the following example: If you run the script with the arguments "C:\Perl Functions" and "C:\Perl Statements", you will call the join.pl script as follows: which it will display: Or if you want to initialize the @ARGV array inside the Perl script, you can simply insert the next line: before the line that contains the join function, and run the script without arguments. It will produce the same output. Please note that it is important to quote the arguments if they contain spaces, for instance if you’ll run the initial join.pl script as follows: you’ll get the output: where you can see that Perl found 4 arguments in the command line (because of spaces). If you want to download the Perl join script with all the above examples included, please click here: Script download To see how to use the Perl join function with array of arrays, try this. (regarding tips and tricks to manipulate multidimensional arrays and hashes in Perl) and you'll receive a link to download for FREE my Perl chomp Function Tutorial eBook (a $7.50 value), it's a bonus for you and I hope you'll enjoy it. You can see its Table of Contents here (if you subscribe to my free newsletter, you don't have to pay for this eBook or use your paypal account). Don't forget to check my new How To Tutorial eBooks (PDF format): to see a lot of fully commented examples that help you use the Perl statements and the Perl buit-in functions in your scripts. NEW!!! Do you want more information about the basic Perl topics? Check my new "Perl How To" Tutorial eBooks page where I'll answer the most frequent questions regarding some topics : Table of Contents: A Perl Script Install Perl Running Perl Perl Data Types Perl Variables Perl Operators Perl Lists Perl Arrays Array Size Array Length Perl Hashes Perl Statements Perl if Perl unless Perl switch Perl while Perl do-while Perl until Perl do-until Perl for Perl foreach Built-in Perl Functions Functions by Category String Functions Array Functions Functions in alphabetical order chomp chop chr crypt defined grep hex index join lc lcfirst length map oct ord pack pop push qw reverse rindex scalar shift sort splice split substr uc undef unshift return from Perl join Function to Perl Basics Hit the Alarm Clock! 
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