Move fun/arity explanation later in getting started (#13890)

Author: sabiwara

lib/elixir/pages/getting-started/anonymous-functions.md

@@ -2,6 +2,32 @@
 
 Anonymous functions allow us to store and pass executable code around as if it was an integer or a string. Let's learn more.
 
+## Identifying functions and documentation
+
+Before we move on to discuss anonymous functions, let's talk about how Elixir identifies named functions.
+
+Functions in Elixir are identified by both their name and their arity. The arity of a function describes the number of arguments that the function takes. From this point on we will use both the function name and its arity to describe functions throughout the documentation. `trunc/1` identifies the function which is named `trunc` and takes `1` argument, whereas `trunc/2` identifies a different (nonexistent) function with the same name but with an arity of `2`.
+
+We can also use this syntax to access documentation. The Elixir shell defines the [`h`](`IEx.Helpers.h/1`) function, which you can use to access documentation for any function. For example, typing `h trunc/1` is going to print the documentation for the `trunc/1` function:
+
+```elixir
+iex> h trunc/1
+                             def trunc(number)
+
+Returns the integer part of number.
+```
+
+`h trunc/1` works because it is defined in the `Kernel` module. All functions in the `Kernel` module are automatically imported into our namespace. Most often you will also include the module name when looking up the documentation for a given function:
+
+```elixir
+iex> h Kernel.trunc/1
+                             def trunc(number)
+
+Returns the integer part of number.
+```
+
+You can use the module+function to lookup for anything, including operators (try `h Kernel.+/2`). Invoking [`h`](`IEx.Helpers.h/1`) without arguments displays the documentation for `IEx.Helpers`, which is where `h` and other functionalities are defined.
+
 ## Defining anonymous functions
 
 Anonymous functions in Elixir are delimited by the keywords `fn` and `end`:

lib/elixir/pages/getting-started/basic-types.md

@@ -81,32 +81,6 @@ false
 
 You can also use [`is_float`](`is_float/1`) or [`is_number`](`is_number/1`) to check, respectively, if an argument is a float, or either an integer or float.
 
-## Identifying functions and documentation
-
-Before we move on to the next data type, let's talk about how Elixir identifies functions.
-
-Functions in Elixir are identified by both their name and their arity. The arity of a function describes the number of arguments that the function takes. From this point on we will use both the function name and its arity to describe functions throughout the documentation. `trunc/1` identifies the function which is named `trunc` and takes `1` argument, whereas `trunc/2` identifies a different (nonexistent) function with the same name but with an arity of `2`.
-
-We can also use this syntax to access documentation. The Elixir shell defines the `h` function, which you can use to access documentation for any function. For example, typing `h trunc/1` is going to print the documentation for the `trunc/1` function:
-
-```elixir
-iex> h trunc/1
-                             def trunc(number)
-
-Returns the integer part of number.
-```
-
-`h trunc/1` works because it is defined in the `Kernel` module. All functions in the `Kernel` module are automatically imported into our namespace. Most often you will also include the module name when looking up the documentation for a given function:
-
-```elixir
-iex> h Kernel.trunc/1
-                             def trunc(number)
-
-Returns the integer part of number.
-```
-
-You can use the module+function to lookup for anything, including operators (try `h Kernel.+/2`). Invoking `h` without arguments displays the documentation for `IEx.Helpers`, which is where `h` and other functionality is defined.
-
 ## Booleans and `nil`
 
 Elixir supports `true` and `false` as booleans: