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.

See Also