Java Reference
In-Depth Information
double y = 3 * (1.0 / 3);
192
193
a.
a ==Ð1Ñ
b.
a ==null
c.
a.equals(ÐÑ)
d.
a == b
e.
a == x
f.
x == y
g.
x Ċ y == null
h.
x.equals(y)
Q
UALITY
T
IP
5.2: Avoid Conditions with Side Effects
In Java, it is legal to nest assignments inside test conditions:
if ((d = b * b - 4 * a * c) >= 0) r =
Math.sqrt(d);
It is legal to use the decrement operator inside other expressions:
if (n-- < 0) . . .
These are bad programming practices, because they mix a test with another
activity. The other activity (setting the variable
d
, decrementing
n
) is called a
side effect of the test.
As you will see in
Advanced Topic 6.2
, conditions with side effects can
occasionally be helpful to simplify loops; for
if
statements they should always
be avoided.
