LOLCODE ~ The Basics...

LOLCODE is an esoteric programming language inspired by the funny things on the Internet. It is designed to test the boundaries of programming language design. This tutorial provides a basic level understanding of the LOLCODE programming language.

This tutorial is meant for people who want to explore beyond general boring programming syntax. Readers of this tutorial can learn the programming language in simple and easy ways.

Programming experience recommended.

Before we get started...

To start your program, write HAI 1.2. This means that your program is running LOLCODE verison 1.2, the newest version. End your program with KTHXBYE. Anything written after the ending of your program will return an error upon execution.

Example:

HAI 1.2
  BTW Write your code here!
KTHXBYE

*IMPORTANT: Every syntax in LOLCODE is in all caps. Make sure that you write it like that, otherwise your LOLCODE program will not run.

1) Printing Statements

To print a string, you use the function VISIBLE. Make sure that you make it ALL CAPS! (Every syntax in LOLCODE is in all caps). Put your string in double quotes.

Example:

VISIBLE "Hello World!"

Output:

Hello World!

2) Comments

Unlike other languages, LOLCODE comments start with the keyword BTW (Slang for 'By the way'). Anything after the BTW is ignored.

Example:

BTW The following code will not execute
BTW VISIBLE "Hello World!"

Multi-line comments in LOLCODE start with the keyword OBTW(Short for 'Oh, by the way') and end with TLDR.

Example:

OBTW
  This is a comment
  Split between
  Multiple lines!
TLDR

*The indentation isn't needed, I just use it because it makes it easier to read.

3) Variables

To declare a variable, use the I HAVE A statement.

Example:

I HAVE A food
BTW my variable is named 'food'
VISIBLE "Yummy!"

Output:

Yummy!

To assign a variable a value, use the keyword ITZ after the declaration of the variable.

Example:

I HAVE A food ITZ "Hamburgers"
I HAVE A number ITZ 100
VISIBLE food
VISIBLE number

*When we are giving the variable food a value of "Hamburgers", we use double quotes around the string, and when we are giving number a value of 100 (an integer), we do not.

You can also assign a variable a value with the R function ('R' stands for 'are').

I HAVE A apple
apple R "Yummy"
BTW apple has the value of "Yummy"

Alternatively, you can also change the value of a variable with the R statement too.

I HAVE A number ITZ 34
BTW 'number' equals 34
number R 57
BTW 'number' now equals 57
VISIBLE number
BTW Prints out 57, not 34

LOLCODE does not allow use of spaces, dashes, or other symbols while naming a variable.

Example:

I HAVE A number$
BTW Returns a error because our variable 'number$' contains '$'

Here are some of the rules for valid and invalid names for variables in LOLCODE:

• The name should always begin with an alphabet. For example, name, Name are valid.
  • The name of a variable cannot begin with a digit. For example, 2var is invalid.
  • The name of a variable cannot begin with a special character.
  • A variable can contain _ or a digit anywhere inside its name, except at the starting index. For example, name2_m is a valid name.

4) Types

Currently, the variable types in LOLCODE are:

- Strings (YARN)
- Integers (NUMBR)
- Floats (NUMBAR)
- Booleans (TROOF)
- Arrays (BUKKIT)

In LOLCODE the variable type is handled dynamically by the compiler. If a variable does not have an initial value, it is called untyped (known as NOOB in LOLCODE).

I HAVE A string ITZ "Hello World!"
BTW 'string' as a value type of 'YARN'

*Boolean values in LOLCODE are WIN and FAIL instead of True and False, like in many other languages.

5) NOOB values

When a variable is declared, but does not have a value, it's value type is untyped, or NOOB.

I HAVE A variable
BTW 'variable' does not have a value, so it's value type is NOOB

A variable is not a NOOB type as soon as a value is assigned to it.

I HAVE A variable 
BTW 'variable' has a value type of NOOB
variable R 100
BTW 'variable' value type is now NUMBR

And also...

I HAVE A decimal ITZ 3.4
BTW 'decimal' immediately has a value type of NUMBAR

6) Operators

Following are the basic mathematical operations in LOLCODE:

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