Basic 7.00 Can Write Whole Array (in TYPE) to Disk at Once (59734)

MORE INFORMATION

Note that you cannot output arrays all at once (in one PRINT# or WRITE# statement) to files opened with sequential access (OPEN FOR OUTPUT). With sequential access (OPEN FOR OUTPUT or INPUT), you must output or input just one array element at a time.

You must use RANDOM or BINARY access to write a static nonvariable-length string array to a file all at once (as shown in the examples below).

Note that in Microsoft QuickBasic versions 4.00, 4.00b, and 4.50 for MS-DOS, in Microsoft Basic Compiler versions 6.00 and 6.00b for MS-DOS and MS OS/2, and in Microsoft Basic PDS versions 7.00 and 7.10 for MS-DOS and MS OS/2, you can directly write whole records (variables) of a given user-defined TYPE to disk as the third argument of the PUT# statement. Each and every element of the user-defined TYPE record is automatically copied to the file. If the data is numeric and you output to a file OPENed with RANDOM or BINARY access, the data is automatically stored in numeric format (without requiring a lengthy FIELD statement or numeric-to-string conversion functions such as MKS$, MKD$, MKI$, or MKL$).

Since an array can be an element of a record of user-defined TYPE in Basic 7.00 and 7.10 (but not in earlier versions), you can write a whole array at once into a disk file, as shown below.

Code Example

The following example, compiled in Basic PDS 7.00 or 7.10, shows how to write a whole array to disk at once, using just one PUT# statement:

TYPE rec1
  array1(20) AS INTEGER
END TYPE
DIM var1 AS rec1, var2 AS rec1  'DIMension var1 & var2 with TYPE rec1
FOR i = 1 TO 20      ' Fill each element of the array:
  var1.array1(i) = i
NEXT

' The following OPEN statements may OPEN FOR either RANDOM or BINARY:
OPEN "test.dat" FOR RANDOM AS #1
PUT #1, , var1       ' Write whole array to disk all at once.
CLOSE

OPEN "test.dat" FOR RANDOM AS #1
GET #1, , var2      ' Reads array all at once into var2.
FOR i = 1 TO 20     ' Print the contents of the array var2.array1:
  PRINT var2.array1(i);
NEXT
CLOSE