Java Reference
In-Depth Information
10.2.
ifelse
The most basic form of conditional control flow is the
if
statement, which
chooses whether to execute statements that follow it. Its syntax is:
if (
expression
)
statement1
else
statement2
First, the expressionwhich must be of type
boolean
or
Boolean
is evaluated.
If its value is
TRue
, then
statement1
is executed; otherwise, if there is an
else
clause,
statement2
is executed. The
else
clause is optional.
You can build a series of tests by joining another
if
to the
else
clause of
a previous
if
. Here is a method that maps a stringexpected to be one of
a particular set of wordsinto an action to be performed with a value:
public void setProperty(String keyword, double value)
throws UnknownProperty
{
if (keyword.equals("charm"))
charm(value);
else if (keyword.equals("strange"))
strange(value);
else
throw new UnknownProperty(keyword);
}
What if there is more than one preceding
if
without an
else
? For ex-
ample:
public double sumPositive(double[] values) {
double sum = 0.0;