Content received from: http://JavaFAQ.nu/java-article386.html
The Java Lesson 3: Identifiers and primitive data types
Wednesday, February 11, 2004 (01:00:00)
Posted by jalex
1. Identifiers in Java | 2. Primitive data types in Java
Identifiers and primitive data types
Uses of identifiers
-
To name a variable (a data area
that takes on different values during processing)
-
To name a method (a module of
code)
-
To name a class (a definition
from which objects can be constructed)
-
To label a statement (for later
referencing)
Rules for identifiers
-
It must not be a
Java keyword
-
It must begin with a letter,
dollar sign ( $ ), or
underscore ( _ )
-
Subsequent characters may be
letters, dollar signs, underscores, or digits
-
Case matters. For example, the
three identifiers MAIN,
Main, and main are different.
Examples of valid
identifiers
yearlyGrossPay
_2002_Budget
JuneActual
$totalAmtDue
Programming
conventions
-
Are not enforced by the
compiler but make it easier to read and maintain Java code
-
Most programmers use "camel
caps" (such as firstQuarterSalesTotal) to handle long identifiers that appear
to contain multiple words. Some use undercores (like first_Quarter_Sales_Totals).
-
Begin variable names, method
names, and labels with a lower case letter. For example, totalAmount, hoursWorked, employeeName, calcBonus, and main.
-
Begin class names with a
capital letter. For example, Person, Customer, SalesRep, and Part.
-
Names of constants should be
all capitals. For example, TAX_RATE, COMMISSION, and DEPOSIT_CODE.
|