Writing our Hello World program

So far, as we have installed the Rakudo Star compiler, it's now time to create the first program in Perl 6. It will print Hello, World! and exit.

The program is really easy. All you need is a single line with the only instruction to call the built-in say function. It takes the string, prints it to the console, and adds a new line after it.

This is how the whole program looks:

say 'Hello, World!'

Save the code to the file, say, hello.pl, and pass it to the compiler as follows:

$ perl6 hello.pl

It will compile the program and immediately execute it. The result is the desired string on the screen:

Hello, World!

Notice that the output ends with a new line. This is the behavior of the built-in say function. Alternatively, we could use another method of printing the output, using the print built-in function. Unlike say, it will not add the new line at the end of the output, so you have to do it yourself by adding the special symbol \n:

print "Hello, World!\n"

Notice that this time, a pair of double quotes is used. Double quotes treat special characters such as \n differently compared to single quotes. Inside double quotes, the \n converts to a new line character. That will not happen in single quotes, and, in that case, \n will appear on the screen as a sequence of two characters, and \n.

Because the program contains only one line of code, it is not necessary to end it with a semicolon. However, you can always do that:

say "Hello, World!";

This program produces exactly the same output as before.