SELECTIONS - Introduction to Java Programming: Comprehensive Version - page 81

If the boolean-expression evaluates to true , the statement(s) for the true case are
executed; otherwise, the statement(s) for the false case are executed. For example, consider
the following code:

if (radius >= 0 ) {
area = radius * radius * PI;
System.out.println( "The area for the circle of radius " +
radius + " is " + area);
}
else {
System.out.println( "Negative input" );
}

two-way if-else statement

If radius >= 0 is true , area is computed and displayed; if it is false , the message
"Negative input" is displayed.
As usual, the braces can be omitted if there is only one statement within them. The braces
enclosing the System.out.println("Negative input") statement can therefore be
omitted in the preceding example.
Here is another example of using the if-else statement. The example checks whether a
number is even or odd, as follows:

if (number % 2 == 0 )
System.out.println(number + " is even." );
else
System.out.println(number + " is odd." );

3.6

✓ ✓

Write an if statement that increases pay by 3% if score is greater than 90 , other-
wise increases pay by 1%.

Check

Point

3.7

What is the output of the code in (a) and (b) if number is 30 ? What if number is 35 ?

if (number % 2 == 0 )
System.out.println(number + " is even." );

if (number % 2 == 0 )
System.out.println(number + " is even." );
else
System.out.println(number + " is odd." );
(b)

System.out.println(number + " is odd." );
(a)

3.5 Nested if and Multi-Way if-else Statements
An if statement can be inside another if statement to form a nested if statement.
The statement in an if or if-else statement can be any legal Java statement, including
another if or if-else statement. The inner if statement is said to be nested inside the outer
if statement. The inner if statement can contain another if statement; in fact, there is no
limit to the depth of the nesting. For example, the following is a nested if statement:

Key
Point

nested if statement

if (i > k) {
if (j > k)
System.out.println( "i and j are greater than k" );
}
else
System.out.println( "i is less than or equal to k" );

The if (j > k) statement is nested inside the if (i > k) statement.
The nested if statement can be used to implement multiple alternatives. The statement
given in Figure 3.3a, for instance, prints a letter grade according to the score, with multiple
alternatives.