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Flash & ActionScript

Vector Graphics

Flash is an efficient way to add animations web pages. It uses vector rather graphics. Vector graphics describes objects using mathmatical equations bit maps. Vector are scalable. They can be resized with no loss of quality.

Flash ActionScript Security

Flash features a programming language called ActionScript. ActionScript is a capable language but it is hampered by security restrictions. Programs execute in a "sandbox". You have a two sandbox models to choose from. One model permits network connections but no local disk access. The other model permits local disk access but no network connections. You could create a program which streams video from the Internet and plays it but you couldn't include an option to simultaneously save it to the local disk. You could create a multi-player network game but you couldn't have it access local disk files.

Object Oriented

ActionScript is an object oriented language. It is similar in may ways to C++, PHP, and Java. An object oriented language differs from procedural languages in that it provides a facility for bundling functions or procedures with the data they manipulate into objects. The variables contained in the objects are known as properties.

Variable Types

Programming languages can be strongly or weakly typed. In a strongly typed language, the type of data a variable holds must be declared when the variable is declared and the data type for the variable can not change thereafter. In a weakly typed language, the variables type is determined when it is assigned a value based upon that value and it can change in a subsequent assignment. ActionScript gives you a choice.

Strongly Typed Example

var moves:Number = 0;

In this example, the variable "moves" can only be set to a numerical value. A subsequent assignment to a string or other non-numeric type would fail.

Weakly Typed Example

var moves = 0;

In this example, even though "moves" is initially assigned a numeric value, it could subsequently be assigned a string value or boolean value.

var moves = "zero";

var moves = false;