WRITE (file statement) - QB64Official/qb64 GitHub Wiki
The WRITE (file statement) file statement writes a list of comma separated variable values to a sequential file or port.
Syntax
WRITE #filenumber&[, expressionList]
Description
- filenumber& is the number of the file or device OPENed in the OUTPUT or APPEND modes. See: FREEFILE.
 - expressionList is a comma-separated list of values to be written to the file or device.
 - WRITE can place any number and types of variable values needed in a file record separated by commas.
 - String values will have quotation marks although quotes are not required to read strings in CSV files with INPUT (file statement) #.
 - Data files using WRITE normally will have the same number of values listed on each file line.
 - Data containing commas must be in quotation marks. Number commas are illegal!
 - WRITE created files are normally read with INPUT #.
 - CSV files created can be read by Excel using a .CSV file name extension. Strings may or may not include quotation marks.
 - Semicolons cannot be used in or following the WRITE statement!
 
Example(s)
Writes new data to a text file sequentially and reads it back to the program screen.
filename$ = "testfile.dat" 
x = 1: y = 2: z$ = "Three" 
OPEN filename$ FOR OUTPUT AS #1 'opens and clears an existing file or creates new empty file 
WRITE #1, x, y, z$ 
CLOSE #1 
PRINT "File created with data. Press a key!" 
K$ = INPUT$(1) 'press a key 
OPEN filename$ FOR INPUT AS #2 'opens a file to read it 
INPUT #2, a, b, c$ 
CLOSE #2 
PRINT a, b, c$
WRITE a, b, c$ 
END 
File content: WRITE string values will include quotation marks, but they are not required to read the file.
1,2,"Three"
Screen output: PRINT string values will not display enclosing quotes. WRITE screen displays will.
 1           2          Three
1,2,"Three"