Functional-Lite JavaScript Exercise 2

Topics:

Functional

Kyle Simpson

You Don't Know JS

This course has been updated! We now recommend you take the Functional-Light JavaScript, v3 course.

Transcript from the "Exercise 2" Lesson

[00:00:00]
>> [MUSIC]

[00:00:03]
>> Kyle Simpson: Pull exercise two up with me. Again, pull up the read me and the EX2.js.
>> Kyle Simpson: I'll go ahead and close exercise one, since we're not using that anymore. Let's look at the read me for exercise two. It says define foo so that it produces a function, we've already seen that, and that function needs to remember only the first two arguments that were passed to foo.

[00:00:26] And then the function that we've returned back, it needs to always add those two together.
>> Kyle Simpson: Parse through that read me.
>> Kyle Simpson: Make sure you fully understand what it's asking for, here's the set up.
>> Kyle Simpson: I should be able to make a function called x that's already remembering the 3 and the 4, and every time I call x I'm gonna get 7 out.

[00:00:53]
>> Kyle Simpson: Not very many lines of code, but let's make sure you have your brains wrapped around how we can use closure, okay?

In this exercise, you will use closure to define a foo() function that returns a function. This returned function remembers only the first two arguments that were passed to foo() and always adds them together.