Publishers of technology books, eBooks, and videos for creative people

Home > Articles > Design > Adobe Creative Suite

ActionScript 3.0 and Math

  • Print
  • + Share This
In this chapter, you'll learn all the basic arithmetic operators that you'll use in ActionScript. Also, there are some convenient shortcuts to make working with math easier that you'll cover as well.
This chapter is from the book

ActionScript has tons of mathematical operators built in to the language to help you evaluate mathematical equations. Now, I wouldn't throw away your handheld calculator just yet. ActionScript has a lot of power, but it's designed to help with your applications, not for general use. In addition to these mathematical operators, there are some functions that can help with common mathematical tasks like rounding numbers.

In this section, you'll learn all the basic arithmetic operators that you'll use in ActionScript. Also, there are some convenient shortcuts to make working with math easier that you'll cover as well.

Mathematical Operators

In ActionScript, you can use simple math operators to perform arithmetic functions with your numbers or variables. The math functions that are part of ActionScript are nearly identical to basic math functions that you already know. Some of the symbols and names are different, but the principles are the same.

Addition and Subtraction

Let's get started with adding and subtracting numbers.

  1. Create a new ActionScript 3.0 project in Flash Professional CS5.5 and enter the following code into the timeline:
    // Math operators: addition and subtraction
    trace ( 2 + 3 );
    trace ( 3 - 2 );
  2. Run the project and look at the Output panel; you'll see the following:
    This shouldn't be surprising, since you are adding and subtracting the numbers. You use the + and operators to indicate that you are adding or subtracting. One thing to note is the white-space characters used in the example. Notice the spaces between the operators and the numbers. This is for readability and doesn't affect the execution of the code. You can remove the spaces if you want, for example:
    trace ( 2 + 3 );
    trace (2+3);
    These two lines perform exactly the same function and will generate the same result.

Addition or Concatenation?

In the previous chapter, you used the + sign, but it wasn't a mathematical operator. You can use the + operator to do two things. When working with strings, the + operator is called the concatenation operator and takes two strings and combines them together, in essence gluing the end of one string to the beginning of the next. When working with numbers, the + operator is the addition mathematical operator, adding two numeric values together and generating a new numeric result.

Look at the following example.

  1. Remove the existing code and enter the following code:
    // Addition vs. Concatenation
    trace ( 2 + 2 ); // addition
    trace ( "two" + "two" ); // concatenation
    trace ( "2" + "2" ); // concatenation
  2. Run this code; you'll see the following displayed in the Output panel:
    The first line of code in the example is pretty simple; you are adding the numbers 2 and 2 using the addition operator, resulting in a value of 4.

    The second line of code has two strings, denoted by quotation marks, that are being "glued" together, creating a single string using the string concatenation operator. The result is "twotwo."

    The last line uses the number 2 on both sides of the operator. Notice that the numbers are surrounded by quotation marks, which means that it is no longer a number value, but instead the character 2. When you force the number 2 to be a string using quotation marks, the + operator concatenates the strings, "gluing" them together forming the string, 22.

    What makes this confusing is that the Output panel doesn't distinguish between strings and numbers. So, when you see 22 in the Output panel, is it a number or a string? There is a way to find out the type of a value and display it: by using the typeof statement.
  3. To see how typeof works, update the previous example as follows:
    // Addition vs. Concatenation
    trace  ( typeof (2 + 2)  ) ; // addition
    trace  ( typeof ("two" + "two")  ) ; // concatenation
    trace  ( typeof ("2" + "2")  ) ; // concatenation
  4. Run this updated example; you'll see the following in the Output panel:
    What is happening is that the operation (either addition or concatenation) is taking place, and the typeof statement is determining the type of the result and then sending that to the Output panel via the trace statement.

    Now for one final twist. If you mix up the number and string types, what happens?

  5. Replace the existing code with the following:
    trace ( 2 + "2" );
    Wow. Now you have a number on the left side, and a string on the right side. Who wins?
  6. Run the project.

    The answer is that the string wins. The result is the string, "22". In this case the operator converts the number 2 to the string "2" and then "glues" it to the right "2" creating the string "22". It seems confusing at first, but after you work with it a while, it will become second nature to you—promise!

Multiplication and Division

Now, look at the * and / operators for multiplication and division.

  1. Replace the code in the timeline with the following:
    // Math operators: Multiplication and Division
    trace ( 2 * 3 );
    trace ( 5 / 2 );
    The first statement uses the multiplication operator, which is an asterisk, *. The division operator is a forward slash, /, and the order of the division is that it divides the value on the left by the value on the right.
  2. Run the project; you'll see the following in the Output panel:

Again, pretty simple stuff—but the next one will probably be new to you.

Modulo, the Operator Formerly Known as Long Division with Remainders

The modulo operator finds the remainder after a division operation. The modulo is quite helpful in many situations, including determining if a number is odd or even. Take a look at how it works.

  1. Replace the code you have with the following, and take a look at the output:
    // Math operators: Modulo
    trace ( 5 % 2 );
  2. Run the project; you'll see the following displayed in the Output panel:
    The % symbol invokes the modulo operator, finding the remainder after attempting a division of the value on the left with the value on the right. In this example, it divides 5 by 2, resulting in 2 and a remainder of 1. To see this written out in long division format, check out Figure 4.1.

    Figure 4.1 5 divided by 2 written in long division format, showing the remainder, or modulo.

  • + Share This
  • 🔖 Save To Your Account

Peachpit Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Peachpit 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 Peachpit 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

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 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 Adobe Press. 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:

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

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