Java Reference
In-Depth Information
Math.sqrt(
4
)
returns
2.0
Math.sqrt(
10.5
)
returns
3.24
5.10.3 The Rounding Methods
The
Math
class contains five rounding methods:
/** x is rounded up to its nearest integer. This integer is
* returned as a double value. */
public static double
ceil(
double
x)
/** x is rounded down to its nearest integer. This integer is
* returned as a double value. */
public static double
floor(
double
x)
/** x is rounded to its nearest integer. If x is equally close
* to two integers, the even one is returned as a double. */
public static double
rint(
double
x)
/** Return (int)Math.floor(x + 0.5). */
public static int
round(
float
x)
/** Return (long)Math.floor(x + 0.5). */
public static long
round(
double
x)
For example,
Math.ceil(
2.1
)
returns
3.0
Math.ceil(
2.0
)
returns
2.0
Math.ceil(
-2.0
)
returns
-2.0
Math.ceil(
-2.1
)
returns
-2.0
Math.floor(
2.1
)
returns
2.0
Math.floor(
2.0
)
returns
2.0
Math.floor(
-
2.0
)
returns
-2.0
Math.floor(
-
2.1
)
returns
-3.0
Math.rint(
2.1
)
returns
2.0
Math.rint(
-
2.0
)
returns
-2.0
Math.rint(
-
2.1
)
returns
-2.0
Math.rint(
2.5
)
returns
2.0
Math.rint(
3.5
)
returns
4.0
Math.rint(
-
2.5
)
returns
-2.0
Math.round(
2.6f
)
returns
3
// Returns int
Math.round(
2.0
)
returns
2
// Returns long
Math.round(
-
2.0f
)
returns
-2
// Returns int
Math.round(
-
2.6
)
returns
-3
// Returns long
Math.round(
-
2.4
)
returns
-2
// Returns long
5.10.4 The
min
,
max
, and
abs
Methods
The
min
and
max
methods are overloaded to return the minimum and maximum numbers of
two numbers (
int
,
long
,
float
, or
double
). For example,
max(3.4, 5.0)
returns
5.0
,
and
min(3, 2)
returns
2
.
The
abs
method is overloaded to return the absolute value of the number (
int
,
long
,
float
, or
double
). For example,
Math.max(
2
,
3
)
returns
3
Math.max(
2.5
,
3
)
returns
3.0
Math.min(
2.5
,
3.6
)
returns
2.5
