Variables:
Containers for data.
Cannot start with a number.
Camel casing.
Cannot be protected words.
Give it a unique name.
Tell it what class of data you want it to store:
Numbers, String, Boolean, Integer, Unsigned Integer, Arrays
var myFirstVariable:Number = 250.5 //any number including decimals
var myInteger:int = 36; //any whole number that is positive or negative
var myUnsignedInteger:uint = 2000; //any positive whole number
var myString:String = "Hello World"; //just plain text
var myBoolean:Boolean = true; //true or false; 1 or 0;
Arrays:
var myFirstArray:Array = new Array(); //creates a new empty array
myFirstArray[0] = "Ross";
myFirstArray[1] = "Higgins";
myFirstArray[2] = 36;
trace(myFirstArray); // send the values of the array to the output panel
Condensed Way to Make an Array:
var mySecondArray:Array = ["Ross", "Higgins", 36];
.push
mySecondArray.push("Married"); //PUSH adds a value to the end of existing array
.pop
mySecondArray.pop(); //POP takes the last one off
.splice
public splice(startIndex:Number, [deleteCount:Number], [value:Object]) : Array
mySecondArray.splice(1,0,"California"); //SPLICE adds a value to the array in a specified position
mySecondArray.splice(1,1); //the position, number of items we are removing
.length
trace("length:" + mySecondArray.length);
OUT PUT:
length:3
HELP:
highlight one of the blue words, like Array, and right click then select View Help
Operators:
== equality operator
> greater than
< less than
>= greater than or equal to
<= less than or equal to
! not operator
!= not equal to
!> greater than
% modulus operator (returns the remainder of the divsion of 2 numbers)
10 % 3 = 1
//10 divide by 3 over and over until it can no longer divide and it gives you the remainder
25 % 5 = 0
//you can use this to check if your array has even values
&& and operator
|| operator
++ increment operator
-- decrement operator
Conditional Statements:
//IF STATEMENTS
if (
myInteger == 362) {
trace("the first statement is true");
} else if (myFirstVariable = 300) {
trace("the second statement is true");
} else {
trace("everything else is false");
}
//AND OPERATOR
if (
myInteger == 36 && myString == "Hello") {
trace("both conditions are true");
}
//OR OPERATOR
if (
myInteger == 36 || myString == "Hello") {
trace("at least one of the conditions are true");
}
//SWITCH STATEMENTS
var a:Number = 35;
switch(a) {
case 0:
trace("#1");
break;
//if you don't have break then it will continue tracing everything below the match
case "Hello World":
trace("#2");
break;
case 35:
trace("#3");
break;
default:
trace("nothing else was a match");
}
Loops:
//FOR LOOPS
//For loops are finite in their execution
//There are 3 parts in constructing Loops :
set up a variable, condition, incrimentor
for(var i:int = 0; i < 5; i++) {
trace("Hello");
}
OUT PUT:
Hello
Hello
Hello
Hello
Hello
//counting up
for(var j:int = 0; j < 10; j++) {
trace(j);
}
OUT PUT:
0
1
2
3
4
5
6
7
8
9
//counting down
for(var k:int = 4; k > 0; k--) {
trace(k);
}
OUT PUT:
4
3
2
1
//WHILE LOOPS
//ends when the condition is met (can create an infinite loop)
var theNumber:Number = 0;
while (theNumber < .5) {
theNumber = Math.random(); //u do this so you don't get infinite loop.
// Math.random will pick numbers above and below .5
trace(theNumber);
}
Random Numbers:
Math.random
Math.random(); //picks a number between 0 - 1; never 0 or 1;
var theRandomNumber:Number = Math.random();
trace(theRandomNumber);
theRandomNumber = Math.random() *5;
trace(theRandomNumber);
rounding
Math.round(); //like elementary school; >= .5 rounds up; < .5 rounds down
Math.ceil(); //always rounds up
Math.floor(); //always rounds down
//(you have to pass a number into the parenthesis to make the above work) Math.round(33);
theRandomNumber = Math.ceil(Math.random() * 100); //pick a random number between 1-100
Functions
1.
function showMessage():void {
}
//void is it's data class. Because we are not returning a value out of the function.
2.
function showMessage():void {
trace("Hello");
}
showMessage();
//call the function
3.
function showMessage(theMessage):void {
trace(theMessage);
}
showMessage("This is Stuff");
showMessage("Hello World");
//pass the information inside the var theMessage into the function
4. Converting to Farenheit
function celciusToFarenheit(theCelciusNumber):Number {
return(9/5) * theCelciusNumber + 32;
}
var theTemperature:Number = celciusToFarenheit(28);
trace(theTemperature);
HOMEWORK:
Read Chapter 1 & 2
