Call a function: Difference between revisions

=={{header|CoffeeScript}}==

<lang coffeescript>

# Calling a function that requires no arguments

foo()

# Calling a function with a fixed number of arguments

foo 1

# Calling a function with optional arguments

# (Optional arguments are done using an object with named keys)

foo 1, optionalBar: 1, optionalBaz: 'bax'

# Calling a function with a variable number of arguments

# for a function `foo` defined as `foo = ( args... ) ->`

foo 1, 2, 3, 4

# Calling a function with named arguments

# (Named arguments are done using an object with named keys)

foo bar: 1, bax: 'baz'

# Using a function in statement context

x = foo 1

# Using a function in first-class context within an expression

# (For `foo` defined as `foo = ( x ) -> x + 1`

x = [ 1, 2, 3 ].map foo

# Obtaining the return value of a function

x = foo 1

# Arguments are passed by value, even objects. Objects

# are passed as the _value_ of the reference to an object.

# Example:

bar = ( person ) ->

# Since `person` is a reference

# to the person passed in, we can assign

# a new value to its `name` key.

person.name = 'Bob'

# Since `person` is just the value of

# the original reference, assigning to it

# does not modify the original reference.

person = new Person 'Frank'

# Partial application is only possible manually through closures

curry = ( f, fixedArgs... ) ->

( args... ) -> f fixedArgs..., args...

# Example usage

add = ( x, y ) -> x + y

add2 = curry add, 2

add2 1 #=> 3

</lang>