Week 2: Functions

Runs once

Runs overand over

Runs each time you click

the mouse

A Brief Detour: Mouse and Key Presses

Runs once

Runs overand over

A Brief Detour: Mouse and Key Presses

Try replacing mousePressed()with:

keyPressed()mouseReleased()mouseDragged()

How are these different?

Functions

(you should know what this does)

Functions

This doesthe same thing…

but with more lines!Why do I care?

Anatomy of a Function(similar words: method, subroutine)

void renderCircle(){ fill(200); ellipse(x,y,100,100);}

what’s this?what’s this?

function code

function name

Do the same thingin slightly different ways

Both circles look the same, but behave

differently

Functions:Why do I care?

If you changethe function code,

you change howthe circles look

without changingtheir behavior

Functions:Why do I care?

make a different shape here

Sometimes it’sjust neater

and easier to read

Functions:Why do I care?

Blahblahblah make 6 ellipses in three alternating colors and enclose them in a rectangle that has a randomly changing color and put a line through it all…

Anatomy of a Function

what’s this?

parameters(TYPE and NAME)

functioncode

function name

void renderCircle(int _x, int _y){ fill(200); ellipse(_x,_y,100,100);}

You can use a function to ask a question

and receive an answer

Functions:Why do I care?

boolean inCircle(int _x, int _y){ if (sq(_x-x) + sq(_y-y) < sq(50)) return true; else return false;}

Anatomy of a Function

data return type

parameters(TYPE and NAME)

functioncode

function name

YOU CAN USEOTHER PEOPLE’S

FUNCTIONS

Functions:Why do I care?