Wednesday, April 13, 2011

In Class Notes // Review

Attaching an External Script
The advantage is that you have 1 file that effects multiple pages, this makes editing easier.

1. The extension has to be .js

2. you add src:
<script type="text/javascript" src="myExternal.js"></script>

3. make sure there is nothing between the <script> tags

The order that you attach scripts is important.

Trouble Shooting
Unfortunately the browsers interpret the scripts differently. The different browsers have tools to help you figure out errors.

Tools >> Error Console
Usually the information presented by the console is useless, but it gives you an idea of the area that is probably causing problems.

More usefull

Webdeveloper: (just for Firefox)
A toolbar extension that is really helpful, in particular with jQuery.

Develop >>> Show Error Console

--------------------------REVIEW of the  READING ASSIGNMENT-------------------------
Operators are Symbols that allow us to manipulate/modify data.
= assignment operator
 (set to the value of)

 Math Operators
+ - * /

Order of operations:
PEMDAS aka Please Excuse My Dear Aunt Sally

M and D have the same weight
A and S have the same weight
so these are performed left to right

(PEMDAS will be on the test)  

Combining Strings
+ the operator use to concatenate
(this is not the same as the mathematical operator + )

var lastName = "Fartyfatkins";
var firstName = "Hugo";

var theName = firstName + ' ' + lastName;


The Point this is to show that you should not have the ' ' (space) in the variable declaration.
var lastName = "Fartyfatkins ";    BAD 

Fixing - Automatic Type Conversion
Number(variable) +Number(variable2)

Changing the Values in Variables 
score = 0;
score = score + 3;
The point is that everything that happens on the right, gets dumped into the left.


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