Binary byte representation of integer
Note: Many $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for the $D2C function is IntegerToBinary. For a full list of string and numeric conversion functions see List of String methods and List of Float methods.
The $D2C function returns a byte string which is the binary equivalent of an integer.
$D2C accepts one required and one optional argument and returns a byte string value.
The first argument is the integer to be converted. If it is omitted, or if after conversion to an integer it is outside the range -2,147,483,647..2,147,483,647, the null string is the result.
The second argument is the number of output bytes in the string. If it is omitted, the first argument must be non-negative, and as many bytes as necessary (1, 2, 3, or 4) are used as the result. If, after conversion to an integer, argument two is not in the range 0..255, the null string is the result.
The returned result is a byte string representing, in binary, the integer part of argument one. If argument two is omitted, the result has as many bytes needed to represent (the non-negative) argument one. Otherwise, the result is sign-extended to as many bytes as specified in argument two, or truncated. A null string is returned for invalid arguments.
%result = $D2C(int_val, width)
%result is set to the width-char binary byte representation of int_val.
- $D2C is similar to the standard $BINARY function, with some differences, such as being able to specify the output length in bytes rather than bits, and being able to specify results of lengths other than 2 or 4 bytes in length.
- The inverse of $D2C is $C2D. See also the $D2X and $X2D functions and the $C2X and $X2C functions.
The following program will print the value
B PRINT $D2C(256 * $X2D('C1') + $X2D('C2')) END
Here are some other results, with the result shown as the hexadecimal representation of the returned byte string, or as ' ' to indicate the null string:
$D2C(9) -> X'09' $D2C(129) -> X'81' $D2C(129, 1) -> X'81' $D2C(129, 2) -> X'0081' $D2C(257, 1) -> X'01' $D2C(-127, 1) -> X'81' $D2C(-127, 2) -> X'FF81' $D2C(-127) -> '' $D2C(-1, 4) -> X'FFFFFFFF' $D2C(12, 0) -> ''