DATA - mkilgore/QB64pe GitHub Wiki

The DATA statement creates a line of fixed program information separated by commas. The DATA can be later READ by the program at runtime.

DATA [value1,]

• DATA is used at the beginning of every data field line with commas separating the values that follow.
• Values can be any literal STRING or numerical type. Variables cannot be used.
• DATA fields can be placed and READ consecutively in the main program code body with or without line labels for RESTORE.
• DATA is best placed after the main program code.
  • QB64 DATA can be placed inside a SUB or FUNCTION procedures.
• RESTORE will only read the first data field if the DATA is not labeled or no label is specified in a RESTORE call.
• When using multiple DATA fields, label each data field with a line label so that each data pointer can be reset for multiple reads with RESTORE linelabel.
• QBasic comma separations were flexible to allow column alignments when creating them. QB64 removes spacing between commas.
• STRING DATA values with end spaces, QBasic keywords and values that include the comma character must be enclosed in quotation marks.
• DATA fields can only be created by the programmer and cannot be changed by a user or lost.
• Comments after a data line require a colon before the comment.
• If a READ statement attempts to read past the last data value, an "Out of Data" error will occur. Use end of data markers when necessary.
• DATA fields can be placed after SUB or FUNCTION procedures, but line labels are not allowed.

Example 1: Creating two DATA fields that can be READ repeatedly using RESTORE with the appropriate line label.

RESTORE Database1
FOR i = 1 TO 18
  READ number%                     'read first DATA field 18 times only
  PRINT number%;                   
NEXT

END

Database1:
DATA 1, 0, 0, 1, 1, 0, 1, 1, 1
DATA 2, 0, 0, 2, 2, 0, 2, 2, 2 :       ' DATA line comments require a colon

Database2:
DATA "Hello, ", "world! ", Goodbye, work! '' ''

Hello world! Goodbyework!
1  0  0  1  1  0  1  1  1  2  0  0  2  2  0  2  2  2

Example 2: How to RESTORE and READ DATA in a SUB procedure in QB64. Line labels can be used for multiple DATA fields.

SUB ReadData (mode)
IF...THEN mode = 1 THEN RESTORE mydata1 ELSE RESTORE mydata2
FOR...NEXT i = 1 TO 10
  READ num(i)
NEXT

mydata1:
DATA 1,2,3,4,5,6,7,8,9,10
mydata2:
DATA 10,9,8,7,6,5,4,3,2,1
END SUB '' '' 

 10  9  8  7  6  5  4  3  2  1 

• READ
• RESTORE
• SUB, FUNCTION