What is ActionScript?

ActionScript has the following basic data types that you use frequently in your programs:

String: A string is a sequence of characters such as letters, numbers, and punctuation marks. You enter strings in an ActionScript statement by enclosing them in single (') or double (") quotation marks.

Ex: var name:String = "Steve";

Number: The number data type is a double-precision floating-point number. The minimum value of a number object is approximately 5e-324. The maximum is approximately 1.79E+308.

Ex: var age:Number = 24;

Boolean: A Boolean value is one that is either true or false. ActionScript also converts the values true and false to 1 and 0 when appropriate. Boolean values are most often used with logical operators in ActionScript statements that make comparisons to control the flow of a script.

Ex: var smoking:Boolean = false;

Object: An object is a collection of properties. Each property has a name and a value. The value of a property can be any Flash data type - even the object data type. This lets you arrange objects inside each other, or nest them. To specify objects and their properties, you use the dot ( .) operator.

Ex:

var user:Object = new Object();

user.name = "Steve";

user.age = 24;

user.sex = "male"

MovieClip: Movie clips are symbols that can play animation in a Flash application. They are the only data type that refers to a graphic element. The MovieClip data type lets you control movie clip symbols using the methods of the MovieClip class.

You do not use a constructor to call the methods of the MovieClip class. You can create a movie clip instance on the Stage or create an instance dynamically. Then you simply call the methods of the MovieClip class using the dot ( .) operator.

Null: The null data type has only one value, null. This value means no value - that is, a lack of data. You can assign the null value in a variety of situations to indicate that a property or variable does not yet have a value assigned to it.

Undefined: The undefined data type has one value, undefined, and is automatically assigned to a variable to which a value hasn't been assigned, either by your code or user interaction.

The value undefined is automatically assigned; unlike null, you don't assign undefined to a variable or property. You use the undefined data type to check if a variable is set or defined.

Void : The void data type has one value, void, and is used in a function definition to indicate that the function does not return a value, as shown in the following example:

Ex:

//Function with a return type Void

function setItem(url:String):Void {

}