Java How to Program Fourth Edition - DCC

Chapter 4 Control Structures: Part 1 157
If studentGrade is greater than or equal to 90, the first four conditions will be true, but
only the System.out.println statement after the first test will be executed. After that
particular System.out.println is executed, the else part of the “outer” if/else
statement is skipped.
Good Programming Practice 4.4
If there are several levels of indentation, each level should be indented by the same additional
amount of space. 4.4
Most Java programmers prefer to write the preceding if structure as
if ( grade >= 90 )
System.out.println( "A" );
else if ( grade >= 80 )
System.out.println( "B" );
else if ( grade >= 70 )
System.out.println( "C" );
else if ( grade >= 60 )
System.out.println( "D" );
else
System.out.println( "F" );
Both forms are equivalent. The latter form is popular because it avoids the deep indentation
of the code to the right. Such deep indentation often leaves little room on a line, forcing
lines to be split and decreasing program readability.
It is important to note that the Java compiler always associates an else with the previous
if unless told to do otherwise by the placement of braces ({}). This attribute is
referred to as the dangling-else problem. For example,
if ( x > 5 )
if ( y > 5 )
System.out.println( "x and y are > 5" );
else
System.out.println( "x is 5" is output. Otherwise, it appears
that if x is not greater than 5, the else part of the if/else structure outputs the string
"x is 5" );
else
System.out.println( "x is 5"—is displayed. However,
if the second condition is false, the string "x is