This document discusses functions in Processing. It explains that functions can be called or defined, and reviews the structure of a function which includes the return type, function name, and argument list. It demonstrates defining a square() function and discusses the benefits of using functions such as organizing code, modularity, reusability, and readability. An example compares organized code using functions versus disorganized code. The document concludes by assigning reading for the next class and mentioning an upcoming quiz.

1. From last time…
•
Global vs. local variable scope!
•
Making static assets with saveFrame()

2. Functions I
CAP

3. Functions Review
void setup() {}
void draw() {}
•
We can do two things with functions:!
! 1. call a function:!
! ! size(500,500);
2. define a function:!
! ! void size(int width, int height) {}

4. Defining a Function
the type of value we expect to be ‘returned’
the arguments we can pass in
returnType functionName( argumentList )
{
// some code goes here
}

5. the variable type we expect to be ‘returned’
the arguments we will pass in
returnType functionName( argumentList )
{
// some code goes here
}
1. Function Name: a name!
2. Input: the variable types of arguments we will pass in!
3. Output: the variable type that will be returned
( void signifies that we do not expect returned value )

6. Demo!
square() function

7. Why functions?
•
Functions organize code in a way that humans
can understand!
•
Modularity: smaller, more readable, more
manageable bits of code; it’s debuggable!!
•
Reusability: you can reuse code within a sketch
(two pong paddles) or between sketches

8. Example
Organized into functions
vs. pure chaos

9. Time Permitting!
Demo!
Make Pong Functions

10. For next time…
•
Read Shiffman, p. 107–119 (Functions II)!
•
Continue (or start) working on Iteration 1
Quiz 2!
Variables, Conditionals, & Loops