Quad-integers are 64-bit (8 byte) signed integers (twice as many bits as Long integers) with a range of -9.22x10^18 to 9.22x10^18 ( -2^63 to 2^63 -1). The type-specifier character for a Quad integer is: &&.
Quad-integer variables are identified by following the variable name with two ampersands (i.e., var&&), or by using the DEFQUD statement as described in the previous discussion of Integers. You can also declare Quad-integer variables using the QUAD keyword with the DIM statement. For example:
DIM I AS QUAD
Although a Quad integer actually has 19 digits of precision, only 18 digits of accuracy can be "displayed" with STR$. A 19-digit value will be rounded to 18 digits in scientific notation when used with STR$. STR$ works with up to 16 significant digits by default, so the enhanced form of STR$ (eg: STR$(var,18)), must be used to generate the 17th and 18th digits of a Quad integer for display purposes.
A C/C++ LARGE_INTEGER and a Delphi int64 are both equivalent to a PowerBASIC Quad integer.
Long integers (&)