getInt64 abstract method
Returns the (possibly negative) integer represented by the eight bytes at
the specified byteOffset
in this object, in two's complement binary
form.
The return value will be between -263 and 263 - 1, inclusive.
The byteOffset
must be non-negative, and
byteOffset + 8
must be less than or equal to the length of this object.
Implementation
int getInt64(int byteOffset, [Endian endian = Endian.big]);