A function is a block of code that provides a value to your Yarn scripts, which you can use in if
statements, or store in variables.
In Yarn Spinner scripts, functions perform two main kinds of task:
Functions let you get values that change over time, or that depend on other values. For example, the random
function returns a different random number every time you call it.
Functions let you get data from your game back into your scripts.
You call a function inside an expression. For example:
Yarn Spinner comes with several built-in functions for you to use.
visited(string node_name)
visited
returns a boolean value of true
if the node with the title of node_name
has been entered and exited at least once before, otherwise returns false
. Will return false
if node_name
doesn't match a node in project.
visited_count(string node_name)
visted_count
returns a number value of the number of times the node with the title of node_name
has been entered and exited, otherwise returns 0
. Will return 0
if node_name
doesn't match a node in project.
random()
random
returns a random number between 0 and 1 each time you call it.
random_range(number a, number b)
random_range
returns a random integer between a
and b
, inclusive.
dice(number sides)
dice
returns a random integer between 1 and sides
, inclusive.
For example, dice(6)
returns a number between 1 and 6, just like rolling a six-sided die.
round(number n)
round
rounds n
to the nearest integer.
round_places(number n, number places)
round_places
rounds n
to the nearest number with places
decimal points.
floor(number n)
floor
rounds n
down to the nearest integer, towards negative infinity.
ceil(number n)
ceil
rounds n
up to the nearest integer, towards positive infinity.
inc(number n)
inc
rounds n
up to the nearest integer. If n
is already an integer, inc
returns n+1
.
dec(number n)
dec
rounds n
down to the nearest integer. If n
is already an integer, dec
returns n-1
.
decimal(number n)
decimal
returns the decimal portion of n
. This will always be a number between 0 and 1. For example, decimal(4.51)
will return 0.51
.
int(number n)
int
rounds n
down to the nearest integer, towards zero.
This is different to floor
, because floor
rounds to negative infinity.
You can define your own custom functions in Yarn Spinner. For more information, see # Defining Commands and Functions .
Functions are not intended to be a way for you to send instructions to your game. For that purpose, you should use commands.
In particular, functions are not guaranteed to be called in the same order as they appear in your code, or even be called at all if Yarn Spinner believes the result can be cached. As much as possible, custom functions should be pure functions, and have no side effects besides returning a value based on parameters.