Java Reference
In-Depth Information
4.27
(Dangling-
else
Problem)
Determine the output for each of the given sets of code when
x
is
9
and
y
is
11
and when
x
is
11
and
y
is
9
. The compiler ignores the indentation in a Java program.
Also, the Java compiler always associates an
else
with the immediately preceding
if
unless told to
do otherwise by the placement of braces (
{}
). On first glance, you may not be sure which
if
a par-
ticular
else
matches—this situation is referred to as the “dangling-
else
problem.” We've eliminat-
ed the indentation from the following code to make the problem more challenging. [
Hint:
Apply
the indentation conventions you've learned.]
a)
if
(x <
10
)
if
(y >
10
)
System.out.println(
"*****"
);
else
System.out.println(
"#####"
);
System.out.println(
"$$$$$"
);
b)
if
(x <
10
)
{
if
(y >
10
)
System.out.println(
"*****"
);
}
else
{
System.out.println(
"#####"
);
System.out.println(
"$$$$$"
);
}
4.28
(Another Dangling-
else
Problem)
Modify the given code to produce the output shown in
each part of the problem. Use proper indentation techniques. Make no changes other than inserting
braces and changing the indentation of the code. The compiler ignores indentation in a Java pro-
gram. We've eliminated the indentation from the given code to make the problem more challeng-
ing. [
Note:
It's possible that no modification is necessary for some of the parts.]
if
(y ==
8
)
if
(x ==
5
)
System.out.println(
"@@@@@"
);
else
System.out.println(
"#####"
);
System.out.println(
"$$$$$"
);
System.out.println(
"&&&&&"
);
a)
Assuming that
x
=
5
and
y
=
8
, the following output is produced:
@@@@@
$$$$$
&&&&&
b)
Assuming that
x
=
5
and
y
=
8
, the following output is produced:
@@@@@
c)
Assuming that
x
=
5
and
y
=
8
, the following output is produced:
@@@@@
d)
Assuming that
x
=
5
and
y
=
7
, the following output is produced. [
Note:
The last three
output statements after the
else
are all part of a block.]
#####
$$$$$
&&&&&
