💬 Q&A Solutions

COND Parameter:

• Tests return codes from previous steps
• Bypasses step if condition is TRUE
• Works opposite to programming logic!
• COND=(4,LT) means: Skip if 4 < any previous RC

IF/THEN/ELSE:

• More intuitive programming-like syntax
• Executes steps when condition is TRUE
• Supports AND, OR operators
• Can check ABEND conditions

Example:

// Using COND (skip if RC < 4)
//STEP2 EXEC PGM=PROG2,COND=(4,LT)

// Using IF/THEN/ELSE
//    IF STEP1.RC = 0 THEN
//STEP2 EXEC PGM=PROG2
//    ELSE
//ERROR EXEC PGM=ERRPROC
//    ENDIF

REDEFINES allows the same storage area to be referenced by different data names with different definitions.

Rules:

• Must be at same level as item being redefined
• Cannot redefine item with OCCURS
• Redefined item must appear first
• Lengths should match or redefining should be shorter

01 WS-DATE.
   05 WS-DATE-NUM    PIC 9(8).
01 WS-DATE-X REDEFINES WS-DATE.
   05 WS-YEAR        PIC 9(4).
   05 WS-MONTH       PIC 9(2).
   05 WS-DAY         PIC 9(2).

Same 8 bytes can be accessed as single number or individual components.

PARM (EXEC statement):

• Limited to 100 characters
• Passed in memory to program
• Accessed via LINKAGE SECTION
• Good for small, simple parameters

SYSIN (DD statement):

• No practical size limit
• Read as a file by program
• Can contain multiple records
• Good for control cards, complex input

// PARM example
//STEP1 EXEC PGM=MYPROG,PARM='PARAM1,PARAM2'

// SYSIN example
//SYSIN DD *
CONTROL OPTION1
DATE=20231215
LIMIT=1000
/*