Words

Characters and Strings Character –A single character inside of single quotes char letter = 'A' ; char digit = '0' ; – Strings Zero or more character in double quotes String word = "hello" ; String robot = "r2d2" ; String nothing = "" ;

Why not string ? String is a class –Classes define data types –Names of classes start with capital letters A convention, not a rule Primitive types –Simplest data types of Java – int, boolean, char, double –Names start with small letters

Odd things to do println('A' + 5) ; println("A" + 5) ; String s = "" ; for (char c = '0'; c < 'Z'; c++) { s = s + c ; } println(s) ;

'5' vs 5 vs "5" '5' is a character encoded as a number –But given from the ASCII standardASCII –That is, '5' is 35 (in Hexadecimal) 5 is the numbers of fingers on one hand "5" is a String –With the single character '5'

'v' vs v 'v' is a character –You cannot do the following 'v' = 30 ; v is a variable name –If appropriately declared int v ; –You can v = 30 ;

Conversion methods boolean –Converts zero to false –Converts non-zero to true byte char int float str –Converts to String

Conversion example println(boolean(5)) ; println(float(5)) ; println(str(5)) ; println(int(5.7)) ; println(str(5.7)) ; println(int('5')) ; println(int('#')) ;

UnicodeUnicode and cut-and-paste char rquote = '‘' ; char lquote = '’' ; char singleQuote = '\''; String dquotes = "“”" ; char oe = 'œ' ; println(int(rquote)) ; println(int(oe)) ;

class and method In object-oriented programming –Classes have methods ≈ functions The operations for that data type –Retrieve information from objects –Modify objects –Methods (and fields) use “dot” operator obj.method(arg1, arg2) –≈ method(obj, arg1, arg2)

Useful methods for s, a String s.length() –Number of characters of s s.charAt(5) –5 th character of s (“first” is 0 th ) s.substring(2, 3) –Characters 2 to 4 of s And many more

Printing on the screen Create a font in Processing environment – Tools » Create Font…. Load font in Processing code – Pfont font = loadFont("……") ; Set font – textFont(font, size) ; Write with font – text("……", x, y) ;

Displaying Text // Step 1: Create the font using the Tool menu option // Step 2: Declare PFont variable PFont f; void setup() { size(200,200); // Step 3: Load Font f = loadFont("Albany-48.vlw“, 40); background(255); textFont(f, 16); // Step 4: Specify font fill(0); // Step 5: Specify font color // Step 6: Display Text text("Mmmmm... Strings...", 10, 100); }

You try it! // Step 1: Create the font using the Tool menu option // Step 2: Declare PFont variable PFont f; void setup() { size(200, 200); // Step 3: Load Font f = loadFont( “you fill this in" ); background(255); textFont(f, “you fill this in”); // Step 4: Specify font fill(0); // Step 5: Specify font color // Step 6: Display Text String message = “you fill this in" ; text (message, 10, 100); }

Useful text functions textWidth("……") –Returns width in pixels of string when printed textAlign(LEFT) textAlign(RIGHT) textAlign(CENTER) –Aligns a text string textSize( n ) –Sets size of font

Try It Again PFont f; void setup() { size(200,200); f = loadFont("Arial-BoldMT-40.vlw"); textFont(f); fill(200); } void draw() { background(255); if(mousePressed && mouseButton == LEFT) { textAlign(LEFT); text ("LEFT", 5, height/2, width, height); } else if(mousePressed && mouseButton == RIGHT) { textAlign(RIGHT); text ("RIGHT", 5, height/2, width, height); }

Lab Load an image of a dog and font into your project Write a Processing program to display the dog along with its name If you have time, animate your dog