Conditionals and Loops - Java Software Solutions: Foundations of Program Design - page 216

The odds of this code picking a winner are based on the value of the CHANCE con-
stant. That is, if CHANCE contains 20, the odds of winning are 1 in 20. The fact that
the condition is looking for a return value of 0 is arbitrary; any value between 0
and CHANCE-1 would have worked.

The if-else Statement
Sometimes we want to do one thing if a condition is true and another thing if
that condition is false. We can add an else clause to an if statement, making it
an if-else statement, to handle this kind of situation. The following is an example
of an if-else statement:

if (height <= MAX)
adjustment = 0;
else
adjustment = MAX - height;

If the condition is true, the first assignment statement is executed;
if the condition is false, the second assignment statement is executed.
Only one or the other will be executed, because a boolean condition
evaluates to either true or false. Note that proper indentation is used
again to communicate that the statements are part of the governing
if statement.

KEY CONCEPT
An if-else statement allows a pro-
gram to do one thing if a condition
is true and another thing if the con-
dition is false.

If Statement

if ( Expression ) Statement

else Statement

An if statement tests the boolean Expression and, if true, executes
the first Statement. The optional else clause identifies the Statement
that should be executed if the Expression is false.
Examples:

if (tal < 7)
System.out.println ("Total is less than 7.");
if (firstCh != 'a')
count++;
else
count = count / 2;