Returns the number of zero bits preceding the highest-order ("leftmost") one-bit in the two's complement binary representation of the specified long value. Returns 64 if the specified value has no one-bits in its two's complement representation, in other words if it is equal to zero.

Note that this method is closely related to the logarithm base 2. For all positive long values x:

floor(log₂(x)) = 63 - numberOfLeadingZeros(x)
ceil(log₂(x)) = 64 - numberOfLeadingZeros(x - 1)

Returns: the number of zero bits preceding the highest-order ("leftmost") one-bit in the two's complement binary representation of the specified long value, or 64 if the value is equal to zero.

Since: 1.5