double getFloat64(
int byteOffset,
[Endianness endian = Endianness.BIG_ENDIAN]
)

Returns the floating point number represented by the eight bytes at the specified byteOffset in this object, in IEEE 754 double-precision binary floating-point format (binary64).

Throws RangeError if byteOffset is negative, or byteOffset + 8 is greater than the length of this object.

Source

/**
 * Returns the floating point number represented by the eight bytes at
 * the specified [byteOffset] in this object, in IEEE 754
 * double-precision binary floating-point format (binary64).
 *
 * Throws [RangeError] if [byteOffset] is negative, or
 * `byteOffset + 8` is greater than the length of this object.
 */
double getFloat64(int byteOffset,
                  [Endianness endian = Endianness.BIG_ENDIAN]);