Editing
Function Clauses in Elixir
(section)
Jump to navigation
Jump to search
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
== Function Clauses in Elixir == Function clauses allow developers to define multiple patterns and implementations for a single function in Elixir. This powerful feature enables pattern matching and polymorphism, allowing functions to behave differently based on the provided inputs. In this article, we will explore the syntax and usage of function clauses in Elixir. === Syntax === The syntax for defining function clauses in Elixir is straightforward. Each clause consists of a function name followed by a set of pattern matching arguments enclosed in parentheses. Here is an example: ```elixir defmodule Math do def add(a, b) do a + b end def add(a, b, c) do a + b + c end end ``` In the above code, we have defined the `add` function with two different clauses. The first clause handles the addition of two arguments, while the second clause handles the addition of three arguments. === Pattern Matching and Overloading === Function clauses in Elixir take advantage of pattern matching to determine which implementation to invoke based on the provided arguments. When a function is called, Elixir will match the arguments against the defined clauses and execute the first matching clause. This allows developers to provide different behavior for different input patterns. ```elixir defmodule Math do def sum([]), do: 0 def sum([head | tail]), do: head + sum(tail) end ``` In the above code, we define the `sum` function with two clauses. The first clause handles an empty list, returning `0`. The second clause handles a list with at least one element by recursively summing the elements. Function clauses also enable function overloading, allowing developers to define multiple clauses with the same function name but different arity (number of arguments). Elixir will select the appropriate clause based on the arity of the provided arguments. === Guard Clauses === Guard clauses further enhance the power of function clauses by allowing additional conditions to be specified for pattern matching. Guard clauses are specified after the pattern matching arguments and are enclosed in the `when` keyword. Here is an example: ```elixir defmodule Math do def divide(a, b) when b != 0 do a / b end def divide(_, 0) do {:error, "Divide by zero"} end end ``` In the above code, we define the `divide` function with two clauses. The first clause handles normal division, but only when the second argument is not zero. The second clause handles the specific case of dividing by zero, returning an error tuple. === Summary === Function clauses in Elixir provide a flexible and powerful way to define functions with different behavior based on pattern matching and arity. By leveraging pattern matching and guard clauses, developers can create expressive and efficient code that adapts to various input conditions. Understanding and using function clauses effectively can greatly improve code readability and maintainability in Elixir projects.
Summary:
Please note that all contributions to Elixir Wiki may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see
Elixir Wiki:Copyrights
for details).
Do not submit copyrighted work without permission!
Cancel
Editing help
(opens in new window)
Navigation menu
Personal tools
Not logged in
Talk
Contributions
Create account
Log in
Namespaces
Page
Discussion
English
Views
Read
Edit
View history
More
Navigation
Main page
Recent changes
Random page
Help about MediaWiki
Tools
What links here
Related changes
Special pages
Page information