The [[FIELD]] statement creates a [[STRING]] type definition for a [[RANDOM|random]]-access file buffer.


{{PageSyntax}}
: [[FIELD]] [#]{{Parameter|fileNumber&amp;}}, {{Parameter|fieldWidth1%}} AS {{Parameter|variable1$}}[, {{Parameter|fieldWidthN%}} AS {{Parameter|variableN$}}]


{{PageDescription}}
* {{Parameter|fileNumber%}} is a file number used in the [[OPEN]] statement or a value from the [[FREEFILE]] function. 
* Combined size of the {{Parameter|fieldWidth%}} parameters '''must not exceed the [[LEN]] = recordsize in the [[RANDOM]] [[OPEN]] statement''' or a [[ERROR Codes|"FIELD overflow" error]] will occur.
* Variables are limited to [[STRING]] types. Use [[TYPE]] instead of FIELD if you want to use numerical values. 
* Once a [[FIELD]] is defined in a statement, [[GET]] can read and [[PUT]] can write data without placeholders or variables.
* [[LSET]], [[RSET]], [[PRINT (file statement)|PRINT #]], [[PRINT USING (file statement)|PRINT # USING]], and [[WRITE (file statement)|WRITE #]] can be used to place characters in the file buffer before a [[PUT]].
* All field definitions for a file are removed when the file is [[CLOSE|closed]] or [[RESET]] and all strings are set to null ("").
* '''Do not re-assign a field defined variable value or use it in an [[INPUT]] statement if you want the variable to remain a field'''.


{{PageExamples}}
''Example:'' Comparing a [[TYPE]] definition with a FIELD [[STRING|string]] definition. Demo using a [[TYPE]] definition to create a file:
{{CodeStart}} '' ''
{{Cl|TYPE}} ClientType
   CName {{Cl|AS}} {{Cl|STRING}} * 30     '30 bytes
   Address {{Cl|AS}} {{Cl|STRING}} * 30   '30 bytes 
   City   {{Cl|AS}} {{Cl|STRING}} * 15    '15 bytes
   State  {{Cl|AS}} {{Cl|STRING}} * 2     ' 2 bytes
   Zip    {{Cl|AS}} {{Cl|STRING}} * 5     ' 5 bytes
{{Cl|END}} {{Cl|TYPE}}      ' total size = 82 bytes
{{Cl|DIM}} Client {{Cl|AS}} ClientType
RecordLEN = {{Cl|LEN}}(Client)       'find the size of each TYPE record

{{Cl|OPEN}} "ADDRESS.DAT" {{Cl|FOR (file statement)|FOR}} {{Cl|RANDOM}} {{Cl|AS}} #1 {{Cl|LEN}} = RecordLEN
{{Cl|RESTORE}} ClientData         'restore to start of DATA
record = 0
{{Cl|DO}}
   {{Cl|READ}} CName$, Address$, City$, State$, Zip$       'read DATA
   {{Cl|IF}} CName$ = "END" {{Cl|THEN}} {{Cl|EXIT DO}}
   record = record + 1               'increment record number
   Client.CName = CName$          
   Client.Address = Address$
   Client.City = City$
   Client.State = State$
   Client.Zip = Zip$
   {{Cl|PUT}} #1, record, Client     'PUT by record number
{{Cl|LOOP}}
{{Cl|CLOSE}} #1 
{{Cl|END}}

ClientData:
   {{Cl|DATA}} "Bob White","104 Birdland Rd.","Bellview","PA","15236"
   {{Cl|DATA}} "Ward Cleaver","123 W. Beaver St.","Beaver","PA","15255"
   {{Cl|DATA}} "Elmer Fudd","45 Wabbit St.","Bethel Park","PA","15022"
   {{Cl|DATA}} "Wyley Coyote","33 Roadrunner Ave.","Clairton","PA","15122"
   {{Cl|DATA}} "Jim Morrison","19 Doorway Dr.","Belleview","PA","15236"
   {{Cl|DATA}} "END",0,0,0,0 '' ''
{{CodeEnd}} '' ''

Demo using the FIELD statement to read the file:
{{CodeStart}} '' ''
{{Cl|CONST}} NM = 30, AD = 30, CT = 15, ST = 2, ZC = 5  ' Define field and record lengths with constants.
{{Cl|CONST}} RLEN = NM + AD + CY + ST + ZC
'
{{Cl|OPEN}} "ADDRESS.DAT" {{Cl|FOR (file statement)|FOR}} {{Cl|RANDOM}} {{Cl|AS}} #1 {{Cl|LEN}} = RLEN
{{Cl|FIELD}} #1, NM {{Cl|AS}} CName$, AD {{Cl|AS}} Address$, CY {{Cl|AS}} City$, ST {{Cl|AS}} State$, ZC {{Cl|AS}} Zip$
{{Cl|FIELD}} #1, RLEN {{Cl|AS}} Clist$         'define entire record

{{Cl|GET}} #1, 1                  'GET does not need a variable to read FIELD records!
                                  'Read file for zip codes from 15230 to 15239 .
{{Cl|DO}} {{Cl|WHILE}} {{Cl|NOT}} {{Cl|EOF}}(1)
   ZipCheck$ = Zip$                            'read zip codes
   {{Cl|IF}} (ZipCheck$ >= "15230" {{Cl|AND (boolean)|AND}} ZipCheck$ &lt;= "15239") {{Cl|THEN}}
      Info$ = Clist$
      {{Cl|PRINT}} {{Cl|LEFT$}}(Info$, 30)     'read name string
      {{Cl|PRINT}} {{Cl|MID$}}(Info$, 31, 30)  'read address string
      {{Cl|PRINT}} {{Cl|RIGHT$}}(Info$, 17)    'read city, state and zip code
      {{Cl|PRINT}}
   {{Cl|END IF}}
   {{Cl|GET}} #1                               'simply GET reads each FIELD record after first
{{Cl|LOOP}}
{{Cl|CLOSE}} #1
{{Cl|END}} '' ''
{{CodeEnd}}


{{PageSeeAlso}}
* [[OPEN]], [[TYPE]]
* [[GET]], [[PUT]]
* [[LSET]], [[RSET]]


{{PageNavigation}}
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