UwU: A cute esolang

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Not to be confused with UwU.

UwU is an esoteric programming language made by PhoenixHO. It is entirely based on UwU faces and UwU-fied english words. A fully functioning bytecode interpreter written in C++ can be found in the external resources.

Language features/syntax

Variables and data-types

UwU is a statically typed esolang that supports working with user-defined variables. It supports the following data-types:

  • Numbers (integers and decimal numbers)
  • Strings
  • Characters
  • Boolean

The syntax for defining a new variable is:

uwu variable_name

without the need to specify the data-type of the variable. To initialize a variable:

uwu variable_name := value

value can be any valid expression in UwU. UwU supports global as well as local variables. Local variables are variables that are declared within a block/scope (enclosed by [: and :]) and only accessible within that block.


Bellow are some valid UwU expressions:

  • number literals (hex currently not supported)
  • character literals (enclosed by backticks `)
  • string literals (enclosed by quotation marks ")
  • boolean (twue or fawse)
  • unary/binary operations


Binary operators:

  • Addition +
  • Subtraction -
  • Multiplication *
  • Division /
  • Concatenation + (works with both character and string literals and the result is always a string)
  • Equality =, != (works with strings too)
  • Comparison <, <=, >, >=
  • Assignent :=

Unary operators:

  • Not !
  • Negation -

Logical operators:

  • awnd
  • ow


UwU supports only multiple line comments. The syntax for them is as follows:

{: This is a comment that will be entirely ignored :}



The syntax for an if-statement in UwU is:

?w? condition [:
    {: code :}

And the syntax for an if..else statement is:

?w? condition [:
    {: will execute if 'condition' is true :}
:] ewe [:
    {: will execute otherwise :}

condition can be any UwU valid expression. UwU treats any non-zero value as truthy, while 0 is falsy.


The syntax for a loop in UwU is:

untiw condition [:
    {: will stop executing if 'condition' is true :}

Print statements

The syntax for printing an expression is:

ouo expression >>

To print multiple expressions at once:

ouo expression1, expression2, ... >>

The new line character in UwU is ~n, while ~t corresponds to the tab character. So to print a new line or a tab:

ouo ~n >>


ouo ~t >>

Reading input

Reading input is different for each data type. The syntax is:

iwi type variable_name <<

type can be:

  • -s for string literals
  • -d for number literals
  • -c for character literals


UwU supports both recursive and non-recursive functions. To define a function:

fwun function_name(parameter1, parameter2, ...) [:
    {: function body :}

    out return_value >>

Parameters and return values are optional.


Hewwo Wowwd!

ouo "Hewwo Wowwd!" >>


uwu input
iwi-d input <<

untiw input = 0 [:
    ouo 1, ~n >>
    iwi-d input <<

External resources