The method
log2(long x, RoundingMode mode) of Guava's
LongMath Class accepts two parameters and calculates the base-2 logarithmic value of the first parameter rounded according to the rounding mode specified by the second parameter.
Syntax:
public static int log2(long x, RoundingMode mode)
Parameters: The method takes 2 parameters, where
x is a long and
mode is a specified rounding mode.
Return Value: This method returns Base-2 logarithm of x, rounded according to the specified rounding mode.
Exceptions: This method throws following parameters:
- IllegalArgumentException: if x <= 0.
- ArithmeticException: if mode is RoundingMode.UNNECESSARY and x is not a power of two.
Enum RoundingMode
| Enum Constant |
Description |
| CEILING |
Rounding mode to round towards positive infinity. |
| DOWN |
Rounding mode to round towards zero. |
| FLOOR |
Rounding mode to round towards negative infinity. |
| HALF_DOWN |
Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down. |
| HALF_EVEN |
Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor. |
| HALF_UP |
Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up. |
| UNNECESSARY |
Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary. |
| UP |
Rounding mode to round away from zero. |
Below examples illustrate the implementation of log2() method of Guava LongMath:
Example 1 :
Example 2:
