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 IEEE vs. Microsoft Binary Format; Rounding Issues (Complete) - Q35826
 
    Method 3
    --------
 
    This method requires the use of a Microsoft C version 5.x or
    later compiler. It uses the C library routine sprintf(). This
    routine takes formatted screen output and stores it in a string
    variable.
 
    C Routine:
 
    struct basic_string {
       int length;
        char *address;
        } ;
 
      void round(number,string)
      double *number;
      struct basic_string *string;
      {
      sprintf(string->address,"%.2f",*number);
      }
 
    Basic Program:
 
    ' To try this example in VBDOS.EXE:
    ' 1. From the File menu, choose New Project.
    ' 2. Copy the code example to the Code window.
    ' 3. Press F5 to run the program.
 
    DECLARE SUB Round CDECL (number#, answer$)
    CLS
    b# = .05#
    FOR i = 1 TO 10
         b# = b# + .01#
         answer$ = SPACE$(50)
         CALL Round(b#, answer$)
         PRINT b#, LTRIM$(RTRIM$(answer$))
         PRINT
         cnt = cnt + 4
         IF cnt > 40 THEN
            cnt = 0
            INPUT a$
         END IF
    NEXT i
 
    The same screen formatting can be accomplished with Basic's PRINT
    USING statement. However, Basic has no direct means of storing this
    information in a string. The information can be sent to a
    Sequential file and then read back into string variables.
 
    You can also write the information to the screen and read this
    information using the SCREEN function. The SCREEN function returns
    the ASCII value of the specified screen location. Consider the
    following example:
 
    ' To try this example in VBDOS.EXE:
    ' 1. From the File menu, choose New Project.
    ' 2. Copy the code example to the Code window.
    ' 3. Press F5 to run the program.
 
    x# = 7.000000000000001D-02
    CLS
    LOCATE 1, 1
    PRINT USING "#################.##"; x#
    FOR i = 1 TO 20
    num = SCREEN(1, i)
    SELECT CASE num
      CASE ASC(".")
        number$ = number$ + "."
      CASE ASC("-")
        number$ = "-"
      CASE ASC("0") TO ASC("9")
        number$ = number$ + CHR$(num)
      CASE ELSE
    END SELECT
    NEXT i
    PRINT number$
 
    The PRINT USING statement would display 17 spaces and then .07. The
    value of number$ would be .07.