Home > Articles

  • Print
  • + Share This
This chapter is from the book

Lesson 19: Duplicating Movie Clips

Being able to manipulate movie clips is an important part of building games. However, you'll also need to be able to create movie clips. Although this is easy enough to do in Flash, you might want your code to be able to create the movie clips after the movie has started running.

Think about a game in which enemy spaceships are attacking the player. One ship comes, and then another, and then another, and so on. Instead of having to create dozens or hundreds of movie clips ready for the game to use, you can have the code create them as necessary.

There are two ways to create movie clips. One is to duplicate a movie clip that already exists. Another is to create a movie clip from a symbol in the library.

To duplicate a movie clip, you need to use the duplicateMovieClip command. This command creates a carbon copy of an existing movie clip. Here is an example:


The command duplicateMovieClip must be triggered by the movie clip to be duplicated. So it starts with the name of that movie clip, in this case "firstclip." There are also two parameters. The first parameter is the name of the new movie clip instance. The second parameter is the level of this new movie clip.

This is where it can get a bit confusing. The duplicateMovieClip command uses the term "level" to describe the order in which movie clips are drawn. This is different than the use of the term "level" in the last section, when it was used to describe which movie clips were inside other movie clips.

If a movie clip is drawn at level 0, like in the previous one-line code example, then it is drawn under a movie clip at level 1. Level 1 is drawn under level 2, and so on.

You don't have to worry about two movie clips being at the same level because they can't be. Flash won't let two movie clips be created at the same level. So with every use of duplicateMovieClip, you need to use a different level number.

Example file: DuplicateMovieClip.fla

In DuplicateMovieClip.fla, the first and only frame of the main timeline contains the variable "level," which is set to 0. On the Stage is a button labeled "New MC." There is also a movie clip with the name "firstclip." Each time the button is pressed, the following code is executed:

on (press) {
  // duplicate first clip

  // set a random position
  _root["newclip"+level]._x = int(Math.random()*550);
  _root["newclip"+level]._y = int(Math.random()*400);

  // increase level


Notice that for the first time, I've used comments in the ActionScript code. These comments start with two slashes. Everything else on a line after the two slashes is ignored by Flash and is there only to make it easier for you to understand what the code is doing. As the blocks of code in this book get longer and longer, you'll see comments to help you read through them. You should also use comments in your code to make it easier to edit later, or for a co-worker to be able to understand it more easily.

The variable "level" is used in many ways in this handler. First, it is used to compose a name for the new movie clip. The first time the variable is used, the movie clip will be named "newclip0." The variable is also used as the level for the movie clip.

At the end of the handler, "level" is incremented by one. So the next movie clip created will be "level1" at level number 1.

This handler also sets the horizontal and vertical location of this new movie clip to a random spot on the Stage. Notice that the _root[] syntax is used to indicate which movie clip is being referred to.

Another way to create new movie clips is to use the attachMovie command. This command does not require that the movie clip already be on the Stage. Instead, it just needs to be in the library. However, if a movie clip is in the library and not used on the Stage, Flash automatically won't include it in the final .swf file. To force it to include this movie clip, you need to select it in the library and use the Options menu to set the Symbol Linkage Properties. You can see this dialog box in Figure 3.5.

Figure 3.5Figure 3.5 The Symbol Linkage Properties dialog box lets you include a movie clip in the .swf even if it isn't used on the Stage.

The Symbol Linkage Properties needs to be set to Export This Symbol. Then, you have to come up with a name for the symbol that the code will use to refer to it. I usually use the symbol's name as it appears in the library.

Example file: AttachMovie.fla

The attachMovie command uses the name in the Symbol Linkage Properties dialog box as the first parameter. The second parameter is the name of the instance of the movie clip on the Stage, and the third parameter is its level. The code for this button, found in the movie AttachMovie.fla, is almost the same as the code for the DuplicateMovieClip.fla movie, with the exception of one line.

on (press) {

  // duplicate first clip

  // set a random position
  _root["newclip"+level]._x = int(Math.random()*550);
  _root["newclip"+level]._y = int(Math.random()*400);

  // increase level

Example file: RemoveMovieClip.fla

You can also remove movie clips from the Stage by using the removeMovieClip command. For instance, the following code, found in RemoveMovieClip.fla, removes the previous movie clip before creating a new one:

on (press) {
  // remove previous movie clip

  // duplicate first clip

  // set a random position
  _root["newclip"+level]._x = int(Math.random()*550);
  _root["newclip"+level]._y = int(Math.random()*400);

  // increase level

These techniques mean that your games and applications can create their own movie clips, adding them and removing them from the Stage as necessary.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020