### 5.7.3.3 Nested IF Constructs

You can include an IF construct in the statement block of another IF construct, if the nested IF construct is completely contained within a statement block. It cannot overlap statement blocks.

The following shows a nested IF construct:

      Form                     Example

      IF (expr) THEN           IF (A .LT. 100) THEN

        block1                   INRAN = INRAN + 1

        IF (expr2) THEN          IF (ABS(A-AVG) .LE. 5.) THEN

          block1a                  INAVG = INAVG + 1

        ELSE                     ELSE

          block1b                  OUTAVG = OUTAVG + 1

        END IF                   END IF

      ELSE                     ELSE

        block2                   OUTRAN = OUTRAN + 1

      END IF                   END IF

If A is less than 100, the code immediately after the IF is executed. This code contains a nested IF construct. If the absolute value of A minus AVG is less than or equal to 5, block1a is executed. If the absolute value of A minus AVG is greater than 5, block1b is executed.

If A is greater than or equal to 100, block2 is executed, and the nested IF construct (in block1) is not executed.

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