Easytrieve Field INITIALization

Initialization Mechanisms Overview

Default Initialization

Without VALUE, numeric working storage fields contain zero at start. Alphabetic W and S fields contain spaces. Predictable for counters WS-COUNT W 4 N starting at zero before loop increments. Do not assume FILE fields are zero on first READ—uninitialized file data may hold LOW-VALUES or prior run residue until validated with IF NUMERIC or FLDCHK debug.

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DEFINE WS-COUNT  W 4 N
DEFINE WS-NAME   W 16 A
* At start: WS-COUNT = 0, WS-NAME = spaces

VALUE Explicit Initialization

VALUE sets initial state at allocation—DEFINE ECHO-SW W 1 A VALUE 'Y' in online examples, DEFINE YEAR W 4 N VALUE 1999 in training manual. Becomes baseline RESET restores. See VALUE page for literal forms and length rules. Use when default zero or blank is wrong for business default flag or constant rate.

RESET Lifecycle

RESET on W field definition tells product to restore field to initial value—including VALUE if present—whenever JOB, SCREEN, or SORT activity executes. Useful for counters and flags that must start fresh each job pass in multi-activity programs. RESET with OCCURS allowed on array W fields. RESET not valid on overlay redefined fields. Multiple RESET fields reset in definition order.

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DEFINE REC-COUNT W 6 N VALUE 0 RESET
DEFINE ECHO-SW   W 1 A VALUE 'Y' RESET
 
JOB INPUT FILE1
  REC-COUNT = REC-COUNT + 1
 
JOB INPUT FILE2
* REC-COUNT restored to 0 by RESET at JOB start
  REC-COUNT = REC-COUNT + 1

Second JOB sees counter zero again because RESET fired at JOB boundary. Without RESET, counter would accumulate across jobs in same run—sometimes desired, often bug.

RESET and Report Spooling

Broadcom notes RESET is not performed during printing of spooled reports when W fields used in report processing. Sequenced reports spool work files—non-static W accumulators may hold values from pre-sequence processing that differ from values at format time. Static S fields or careful job design avoids wrong averages. Read Getting Started warning on W-type fields in sequenced reports before building scratch totals.

FILE Field Initialization From Dataset

FILE fields receive record bytes on READ or PUT context. New VSAM file initialization job sets CUST-ID = 0 and NEXT-ID = 1 then PUT CUST—assignment in JOB, not VALUE on FILE DEFINE. First record seeds control file. Batch programs reading production extracts inherit whatever upstream wrote—validate before arithmetic.

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JOB INPUT NULL
  CUST-ID = 0
  NEXT-ID = 1
  PUT CUST
  STOP

Runtime MOVE Initialization

Activity logic clears buffers before building output records. MOVE SPACE TO alpha fields, zero patterns to numeric groups. Example from manuals: initialize numeric and alpha fields before concatenation or PUT. Runs every time statement executes—not once at compile like VALUE. Use inside PROC before writing trailer or after reading header.

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INIT-RECORD. PROC
  MOVE SPACE TO OUT-NAME OUT-ADDR
  WS-AMT = 0
END-PROC

VARYING Field Initial State

Varying alphanumeric default is zero-length string until VALUE supplies default content and length. Fixed-length beginners encounter this when advancing to variable-length name fields in online programs.

Initialization vs Validation

Initialization sets starting value. Validation checks after READ—IF ACCT NUMERIC, IF DATEVAL YES. LOW-VALUES in file numeric fields pass initialization concept but fail validation—use FLDCHK in PARM DEBUG during test. Do not conflate initialized working storage with clean file data.

Choosing the Right Approach

1. Default zero or blank sufficient—omit VALUE for counters starting at zero.
2. Known constant at compile—VALUE on DEFINE.
3. Fresh counter each JOB—VALUE 0 with RESET.
4. Per-record output buffer—MOVE or assignment in PROC each iteration.
5. New file seed record—assignment plus PUT in init JOB.

Common INITIAL Mistakes

• Expecting VALUE to zero FILE fields before READ.
• Missing RESET when second JOB should restart counter.
• Using W accumulator in sequenced report without understanding spool timing.
• Assuming uninitialized FILE numeric is zero—test with DISPLAY HEX.
• RESET on overlay field—invalid per documentation.

Explain It Like I'm Five

Initialization is setting up toys before play. Empty number toys start at zero, letter toys start blank. VALUE puts a sticker saying start at five instead. RESET cleans the toy back to the sticker number when a new game round starts. File toys come filled from the delivery box— you do not choose their starting stuff from home stickers.

Exercises

1. Define counter with VALUE 0 and RESET; explain second JOB behavior.
2. Write init JOB putting CUST-ID zero and NEXT-ID one.
3. State default for W 10 A without VALUE.
4. Contrast VALUE with MOVE SPACE in PROC.
5. Explain why FILE GROSS is not initialized by VALUE.