Conditional Commands › IF

IF

Purpose

Evaluates one or more conditional expressions and specifies actions based on the outcome of the evaluation.

Syntax

►►─── IF conditional-expression ──────────────────────────────────────────────►

 ►─── then ──────┬─ command-statement. ────────────────────┬──────────────────►
                 │       ┌───────────────────────┐         │
                 └─ DO. ─▼─ command-statement. ──┴─ END. ──┘

 ►─┬─────────────────────────────────────────────────────────┬────────────────►◄
   └─ ELSE ──────┬─ command-statement. ────────────────────┬─┘
                 │       ┌───────────────────────┐         │
                 └─ DO. ─▼─ command-statement. ──┴─ END. ──┘

Parameters

conditional-expression

Specifies the conditional expression to be evaluated. The outcome of the evaluation determines the processing that occurs.

Conditional-expression contains one or more conditions to be evaluated and is specified according to the rules presented in Conditional Expressions.

then command-statement

Specifies the commands to be executed if the condition is true.

Multiple command statements must be preceded by DO and followed by END.

Command-statement can be any valid CA ADS process command, including another conditional command.

ELSE command-statement

Specifies the commands to be executed if the condition is false.

Multiple command statements must be preceded by DO and followed by END.

Usage

Considerations

• An entire conditional expression is evaluated before a result is returned.
  • If the outcome is true, CA ADS executes the commands following the conditional expression.
  • If the outcome is false, CA ADS bypasses commands following the conditional expression and executes commands that specify alternative processing.
• If no alternative processing commands exist for a false outcome, CA ADS proceeds to the next executable command outside the IF statement.
• IF commands can be nested to any level.

  Indentation should be used wherever possible to make statements more readable and to ensure that the required clauses are properly matched.

• A given IF statement can include only one ELSE clause, and that ELSE clause must match the most recent IF command not associated with an ELSE clause.

Example 1: Using a simple IF command

In this example, a simple IF command tests the status of a map field and executes a DISPLAY command if the condition is true:

IF FIELD PROD-NUM IS NOT CHANGED
THEN
    DISPLAY MSG TEXT IS 'ENTER PRODUCT NUMBER'.

Example 2: Using an IF command with an ELSE clause

This example includes an ELSE clause to display an alternative message if the field ERROR-FIELD contains 0:

IF ERROR-FIELD NE '0'
THEN
    DISPLAY MSG CODE IS 171075 PARM=(MSG-NUM).
ELSE
    DISPLAY MSG TEXT IS 'ENTER NEXT PRODUCT NUMBER'.

Example 3: Using a nested IF command

This example illustrates a nested IF command that tests for CA-INDX if DB-END-OF-SET is reached:

IF DB-END-OF-SET
THEN
    IF CA-INDX EQ 1
    THEN
      DO.
        MOVE 'NO CUSTOMERS QUALIFY' TO MSG-FIELD.
        MOVE '1' TO ERROR-FIELD.
        RETURN.
      END.
    ELSE
        DISPLAY MSG TEXT IS 'CUSTOMER NUMBER LIST COMPLETE'.
ELSE
    DISPLAY MSG TEXT IS 'ADDITIONAL CUSTOMERS MAY QUALIFY'.