Java Reference
In-Depth Information
as blocks .
Thissection introduces youtomanyofJava'sstatements. Additional statements are
covered in later chapters. For example, Chapter 2 discusses the return statement.
Assignment Statements
The assignment statement isanexpressionthatassignsavaluetoavariable.Thisstate-
mentbeginswithavariablename,continueswiththeassignmentoperator( = )oracom-
poundassignmentoperator(suchas += ),andconcludeswithanexpressionandasemi-
colon. Below are three examples:
x = 10;
ages[0] = 25;
counter += 10;
The first example assigns integer 10 to variable x , which is presumably of type in-
tegeraswell.Thesecondexampleassignsinteger 25 tothefirstelementofthe ages
array.Thethirdexampleadds 10 tothevaluestoredin counter andstoresthesumin
counter .
Note Initializing a variable in the variable's declaration (e.g., int counter =
1; ) can be thought of as a special form of the assignment statement.
Decision Statements
Thepreviouslydescribedconditionaloperator( ?: )isusefulforchoosingbetweentwo
purpose, Java supplies three decision statements: if, if-else, and switch.
If Statement
The if statement evaluates a Boolean expression and executes another statement when
this expression evaluates to true. This statement has the following syntax:
if ( Boolean expression )
Ifconsistsofreservedword if ,followedbya Boolean expression inparen-
theses,followedbya statement toexecutewhen Boolean expression evalu-
ates to true.
The following example demonstrates this statement:
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