Flow of Control - Java - page 96

Compound Statements

if-else with
multiple
statements
compound
statement

You will often want the branches of an statement to execute more than one

statement each. To accomplish this, enclose the statements for each branch between a
pair of braces,

if-else

{

and

}

. A list of statements enclosed in a pair of braces is called a com-

. A compound statement is treated as a single statement by Java and
may be used anywhere that a single statement may be used. Thus, the “Multiple State-
ment Alternatives” version described in the box entitled “

pound statement

Statement” is really
just a special case of the “simple” case with one statement in each branch.

if-else

Statement

if-else

The if-else statement chooses between two alternative actions based on the value of a

Boolean_Expression ; that is, an expression that is either true or false , such as balance < 0 .

SYNTAX

if ( Boolean_Expression )

Be sure to note that the
Boolean_Expression must
be enclosed in parentheses.

Yes_Statement

else
No_Statement

If Boolean_Expression is true , then Yes_Statement is executed. If Boolean_Expression is
false , then No_Statement is executed.
EXAMPLE

if (time < limit)
System.out.println("You made it.");
else
System.out.println("You missed the deadline.");

Omitting the else Part
You may omit the else part to obtain what is often called an if statement .
Syntax

if ( Boolean_Expression )
Action_Statement

If Boolean_Expression is true, then Action_Statement is executed; otherwise, nothing hap-
pens and the program goes on to the next statement.
EXAMPLE

if (weight > ideal)
calorieAllotment = calorieAllotment - 500;