The document explains JavaScript functions as reusable, modular code that can be defined and executed later. It covers the definition of functions, the use of arguments, and the significance of the return statement in capturing values. It also illustrates examples of functions with and without inputs and the use of return values.

1. JavaScript
Functions
Web Developer Bootcamp
THE LAST "BIG" TOPIC!

2. FUNCTIONS
Reusable procedures
Functions allow us to write
reusable, modular code
We define a "chunk" of code that
we can then execute at a later
point.
We use them ALL THE TIME

3. 2 STEP PROCESS
DEFINE RUN

4. DEFINE
function funcName(){
//do something
}

5. DEFINE

6. RUN
funcName(); //run once
funcName(); //run again!

7. RUN

8. ARGUMENTS

9. INPUTS
Right now, our simple functions
accept zero inputs. They behave the
same way every time.

10. NO INPUTS
grumpus()
grumpus()

11. NO INPUTS
greet() "Hi!"
greet() "Hi!"

12. ARGUMENTS
We can also write functions that accept
inputs, called arguments

13. ARGUMENTS
greet('Tim') "Hi Tim!"
greet('Anya') "Hi Anya!"

14. ONE MORE
avg(20,25) 22.5
avg(3,2,5,6) 4

15. No inputs
Arguments!
We've seen this before

16. GREET TAKE 2
"Hi, Arya!" "Hi, Ned!"

17. 2 ARGUMENTS!
"77 is
larger!"
"33 and 33
are equal"

18. RETURN
Built-in methods return values
when we call them.
We can store those values:

19. NO RETURN!
Our functions print values out, but do
NOT return anything

20. FIRST RETURN!
Now we can capture a return
value in a variable!

21. RETURN
The return statement ends function
execution AND specifies the value to be
returned by that function