Heads up! To view this whole video, sign in with your Courses account or enroll in your free 7-day trial. Sign In Enroll
Preview
Start a free Courses trial
to watch this video
In this video, we'll convert our function declaration into an anonymous function.
Anonymous Functions
An anonymous function is a function without a name.
function ( ) {
//Do something
}
Related Discussions
Have questions about this video? Start a discussion with the community and Treehouse staff.
Sign upRelated Discussions
Have questions about this video? Start a discussion with the community and Treehouse staff.
Sign up
Another common way you'll encounter and
0:00
write callback functions
is as anonymous functions.
0:02
An anonymous function is
a function without a name.
0:05
In the case of a callback an anonymous
function can be written in place or
0:09
in line where the name of
the function would be.
0:14
Let's convert sayHello into
an anonymous function.
0:17
With practice, you can jump these
steps that I'm going to take.
0:21
But for now, I'll show my work.
0:25
First, I can change my sayHello
function from a function
0:28
declaration to a function
expression by adding a variable,
0:32
sayHello, And
deleting the name of the function.
0:37
Now to convert this function
to an anonymous function,
0:46
I can just get rid of the variable name.
0:50
How do we pass the anonymous function into
the executeCallback without a reference?
0:53
The function doesn't have a name anymore.
0:59
We can write it in place
of the sayHello name.
1:02
We can do that by cutting and
1:06
pasting the anonymous function
over the sayHello name.
1:11
When writing a function like this,
this is also know as inlining or
1:16
writing a function in line.
1:21
It can be more expressive.
1:23
You can clearly see a function
as a parameter here,
1:25
which isn't always obvious
when you use a named function.
1:29
You can see it's a callback, and
1:33
that the function could get executed
at any given point in the future.
1:35
A callback function is more obvious when
it's written as an anonymous function.
1:40
I've got a small challenge for
1:45
you, write another anonymous
function that will print goodbye.
1:47
Pause the video, and
then I'll show you how I did it.
1:52
I can just copy and paste the execute
callback and replace hello with goodbye.
1:57
You need to sign up for Treehouse in order to download course files.
Sign upYou need to sign up for Treehouse in order to set up Workspace
Sign up