Home > Articles > Programming > Java

The ABCs of Java

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

Literals

In addition to variables, you will also use a literal in a Java statement.

New Term

A literal is any number, text, or other information that directly represents a value.

Literal is a programming term that essentially means that what you type is what you get. The following assignment statement uses a literal:

int year = 2000;

The literal is 2000, because it directly represents the integer value 2000. Numbers, characters, and strings all are examples of literals.

Although the meaning and usage of literals will seem intuitive most of the time, Java has some special types of literals that represent different kinds of numbers, characters, strings, and Boolean values.

Number Literals

Java has several integer literals. The number 4, for example, is an integer literal of the int variable type. It also can be assigned to byte and short variables because the number is small enough to fit into those integer types. An integer literal larger than an int can hold is automatically considered to be of the type long. You also can indicate that a literal should be a long integer by adding the letter L (L or l) to the number. For example, the following statement treats the value 4 as a long integer:

pennyTotal = pennyTotal + 4L;

To represent a negative number as a literal, prepend a minus sign (-) to the literal, as in -45.

If you need to use a literal integer with octal numbering, prepend a 0 to the number. For example, the octal number 777 would be the literal 0777. Hexadecimal integers are used as literals by prepending the number with 0x, as in 0x12 or 0xFF.

NOTE

Octal and hexadecimal numbering systems are convenient for many advanced programming uses, but unlikely to be needed by beginners. Octal numbers are a base-8 numbering system, which means they can only represent the values 0 through 7 as a single digit. The eighth number in octal is 10 (or 010 as a Java literal).

Hexadecimal is a base-16 numbering system, and it can represent 16 numbers as a single digit. The letters A through F represent the last six digits, so the first 16 numbers are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F.

The octal and hexadecimal systems are better suited for certain tasks in programming than the normal decimal system is. If you have ever used HTML to set a Web page's background color, you might have used hexadecimal numbers.

Floating-point literals use a period character (.) for the decimal point, as you would expect. The following statement uses a literal to set up a double variable:

double myGPA = 2.25;

All floating-point literals are considered of the double variable type instead of float. To specify a literal of float, add the letter F (F or f) to the literal, as in the following example:

float piValue = 3.1415927F;

You can use exponents in floating-point literals by using the letter e or E followed by the exponent, which can be a negative number. The following statements use exponential notation:

double x = 12e22;
double y = 19E-95; 

Boolean Literals

The Boolean values true and false also are literals. These are the only two values you can use when assigning a value to a boolean variable type or using a Boolean in a statement in other ways.

If you have used another language such as C, you might expect that a value of 1 is equivalent to true and 0 is equivalent to false. This isn't the case in Java—you must use the values true or false to represent Boolean values. The following statement sets a boolean variable:

boolean chosen = true;

Note that the literal true does not have quotation marks around it. If it did, the Java compiler would assume that it was a string of characters.

Character Literals

Character literals are expressed by a single character surrounded by single quotation marks, such as 'a', '#', and '3'. You might be familiar with the ASCII character set, which includes 128 characters including letters, numerals, punctuation, and other characters useful in computing. Java supports thousands of additional characters through the 16-bit Unicode standard.

Some character literals represent characters that are not readily printable or accessible through a keyboard. Table 3.2 lists the special codes that can represent these special characters as well as characters from the Unicode character set. The letter d in the octal, hex, and Unicode escape codes represents a number or a hexadecimal digit (a–f or AF).

Table 3.2 Character Escape Codes

Escape

Meaning

\n

New line

\t

Tab

\b

Backspace

\r

Carriage return

\f

Formfeed

\\

Backslash

\'

Single quotation mark

\"

Double quotation mark

\d

Octal

\xd

Hexadecimal

\ud

Unicode character


NOTE

C and C++ programmers should note that Java does not include character codes for \a (bell) or \v (vertical tab).

String Literals

The final literal that you can use in a Java program represents strings of characters. A string in Java is an object rather than being a basic data type, and strings are not stored in arrays as they are in languages such as C.

Because string objects are real objects in Java, methods are available to combine strings, modify strings, and determine whether two strings have the same value.

String literals consist of a series of characters inside double quotation marks, as in the following statements:

String quitMsg = "Are you sure you want to quit?";
String password = "swordfish";

Strings can include the character escape codes listed in Table 3.2 previously, as shown here:

String example = "Socrates asked, \"Hemlock is poison?\"";
System.out.println("Sincerely,\nMillard Fillmore\n");
String title = "Sams Teach Yourself Rebol While You Sleep\u2122"

In the last example here, the Unicode code sequence \u2122 produces a !" symbol on systems that have been configured to support Unicode.

CAUTION

Most users in English-speaking countries aren't likely to see Unicode characters when they run Java programs. Although Java supports the transmission of Unicode characters, the user's system also must support it for the characters to be displayed. Unicode support provides a way to encode its characters for systems that support the standard. Although Java 1.0 supported only the Latin subset of Unicode, Java 1.1 and subsequent versions support the display of any Unicode character that can be represented by a host font.

For more information about Unicode, visit the Unicode Consortium Web site at http://www.unicode.org.

Although string literals are used in a manner similar to other literals in a program, they are handled differently behind the scenes.

When a string literal is used, Java stores that value as a String object. You don't have to explicitly create a new object, as you must do when working with other objects, so they are as easy to work with as basic data types. Strings are unusual in this respect—none of the basic types is stored as an object when used. You learn more about strings and the String class today and tomorrow.

  • + 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.

Overview


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.

Surveys

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.

Newsletters

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.

Security


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

Children


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

Marketing


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.

Choice/Opt-out


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.

Links


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