language

Numberso Numbers represent any integral or

fractional number.

1, 1.5, -10

o All the usual arithmetic operators are available.

1 + 2, 3 / 2.5, 10 < 20, 5 = 5o More math goodness in math

math->sin(3.2)

Texto A piece of text is called a String.

"Hello"o You can glue strings together using ||

"Hello " || "world"o You can access the number of characters

(count) and each character individually (at).

"Hello"->count 5 "Hello"->at(0) H

local variableso a local variable holds a value in

memory; a local variable can be read or written too.• definition

var x := 0

• reading

x->post to wall

• update with new value

x := 5

while loopso while loop: repeats the same code while

the condition holds

• definition

while ... do...

true or false

happens when true

for loopso for loop: repeats the same code

multiple times• definition

for 0 ≤ index < count do...

• index starts at 0, increments by 1 on each iteration and finishes at count-1.

index goes through 0, 1, 2, … , count-1

for each loopso for each loop: repeats the same

code for each element of a collection• definition

for each song in media->songs do ...

song goes through every song in songs

Boolean valueso a Boolean value may be true or

false• definition

var b := true var c := false

if statement: executes different code based on a Boolean condition

if ...

then ...

else ...

if .. then .. else ..

true or false

happens when true

happens when false

actionsfunctions: a collection of lines of code with a name that one can call. Functions can have inputs and outputs.

action square(x : Number) returns r : Number r := x * x

x is an input, it is a number

r is an output, it is a number

the action is called ‘square’

storing x*x into r

‘not’ operator

o examples

not true false

false

true

not true = falsenot false = truenot (not true) = true

‘or’ operator

o examples

true or false = true

false or true = true

false or false = false

or true false

true true truefalse true fals

e

‘and’ operator

o examples• true and false = false

• false and true = false

• true and true = true

and true falsetrue true falsefalse

false

false

arithmetic operatorso compares 2 numbers and returns a

Boolean value

• x < y = true if x is less than y; otherwise x < y = false.

• x ≤ y = true if x is less or equal than y; otherwise x ≤ y = false.

global variableso a global variable is variables available in all

actions and events; a global variable can be read or written to.• global variables are stored under data. In the

editor, data-> is shortened to the square symbol.

• reading

data->x->post to wall

• update with new value

data->x := 5

o the scope of a local variable is the area of code where this local variable exists; the scope is the outermost block of code.action go() var x := 0 for 0 ≤ index < count do var y : = 0

scope

scope of x

scope of y

while vs foro a for loop can be written as a while loop

• for:

• while:

var index := 0while index < 10 do index->post to wall index := index + 1

for 0 ≤ index < 11 do index->post to wall