ActionScript for Flash MX: The Definitive Guide, Second Edition

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Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

Further ActionScript Concepts

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13

Putting It All Together

Let’s review what you’ve learned. Here, again, is line one of our example:

var message = "Hi there, Flash!";

The keyword var tells the interpreter that we’re declaring (creating) a new variable.

The word

message is the name of our variable (a name we’ve chosen arbitrarily). The

equals sign is an operator that assigns the text string (“Hi there, Flash!”) to the vari-

able named

message. Hence, the text “Hi there, Flash!” becomes the value of message.

Finally, the semicolon (

;) tells the interpreter that we’re finished with our first state-

ment.

Line two is pretty much the same as line one:

var firstName = "your name here";

It assigns the text string you typed in place of your name here to the variable

firstName. A semicolon ends our second statement.

We reuse the variables

message and firstName in lines three and four:

trace (message);

trace ("Hi there, " + firstName + ", nice to meet you.");

The keyword trace tells the interpreter to display some text in the Output window.

We pass the text to be displayed as an argument. The opening parenthesis marks the

beginning of our argument. The trace( ) command requires one argument, but that

argument might be a fairly complex expression. For example, in line four, the argu-

ment includes two