HAI 1.2 VISIBLE "Hello, World!" KTHXBYE
Yes, that was a "Hello, World!" program in the famous LOLCODE programming language.
LOLCODE is an esoteric programming language, a type of programming language which is defined by the Esolang Wiki as follows:
An esoteric programming language is a computer programming language designed to experiment with weird ideas, to be hard to program in, or as a joke, rather than for practical use.
LOLCODE was written to be programming language to mimic the "lolcats" meme which became popular in the mid-2000s, with basic syntax including words such as
HAI (start program with version number) and
KTHXBYE (end program).
Like many other esoteric programming languages, LOLCODE is actually very featured, and has the capability to be used to write many complex programs.
In fact, Justin Meza, the creator of the most recent LOLCODE interpreter, created httpd.lol, an HTTP server written entirely in LOLCODE.
Let's Write a Basic LOLCODE Program
KTHXBYE for starting and ending programs
Every LOLCODE program starts with a
HAI declaration, followed by a version number. For example:
HAI declaration, the end of every program must include a
KTHXBYE statement, for example:
HAI 1.2 KTHXBYE
OBTW for comments
BTW keyword introduces a single line comment, like this:
BTW this is a single line comment
TLDR keywords are used to start and end a multiline comment respectively, for example:
OBTW This is a multiline comment TLDR
VISIBLE for printing to stdout
To print text in LOLCODE, the
VISIBLE keyword is used as follows:
VISIBLE "Hello, World!"
I HAS A [varname] ITZ [value]
Variables in LOLCODE are written with the syntax
I HAS A [var] ITZ [value], for example:
BTW this sets the variable NAME to the value "FRED ADAMS" I HAS A NAME ITZ "FRED ADAMS"
Variables can then be referenced later with the same name.
AN for concatenation
To concatenate strings and variables,
SMOOSH is used. Example is provided in basic program below.
A Basic Program to Concatenate Strings and Variables
Now, we'll combine these basic LOLCODE keywords and syntax to create a very, very basic program which concatenates strings and variables.
The Python equivalent of this would be:
name = "Fred Adams" website = "xtrp.io" favorite_color = "blue" print("Hi, I am " + name + ", my website is at " + website + " and my favorite color is " + favorite_color + ".")
Which in LOLCODE is:
HAI 1.2 OBTW This program creates several variables, concatenates them, and prints them. TLDR BTW create variables I HAS A NAME ITZ "Fred Adams" I HAS A WEBSITE ITZ "xtrp.io" I HAS A FAVORITECOLOR ITZ "blue" BTW concatenate with SMOOSH and AN VISIBLE SMOOSH "Hi, I am " AN NAME AN ", my website is at " AN WEBSITE AN " and my favorite color is " AN FAVORITECOLOR AN "." KTHXBYE
And produces the following output successfully:
Hi, I am Fred Adams, my website is at xtrp.io and my favorite color is blue.
Note that some interpreters may require LOLCODE programs to include the
STDIO library, which can be included with a
CAN HAS [library]? statement.
I hope you enjoyed this post and found LOLCODE to be a funny yet interesting programming language. You can read more about LOLCODE and its syntax on the LOLCODE Esolang Wiki Page, and check out The LOLCODE Website.
Thanks for scrolling.
— Fred Adams, January 11, 2020