iTS 1.0+)

Procedure Division

Compaq NonStop™ Pathway/iTS SCREEN COBOL Reference Manual—426750-001

6-53

PERFORM Statements

The range of a PERFORM statement is logically all those statements that are executed

as a result of the PERFORM statement, through the transfer of control to the statement

following the PERFORM statement. The range includes all statements executed

as a result of a GO TO, PERFORM, or CALL statement in the range of the original

PERFORM statement, as well as all statements in the Declaratives Section that might be

executed. Statements in the range of a PERFORM are not required to appear

consecutively.

If a sequence of statements referred to by a PERFORM statement includes another

PERFORM statement, the sequence of procedures for the nested PERFORM must be

either totally included in, or totally excluded from, the logical sequence referred to by

the original PERFORM statement. Thus, an active PERFORM statement whose

execution point begins within the range of another active PERFORM statement must not

allow control to pass to the exit of the other active PERFORM statement. Furthermore,

two or more such active PERFORM statements must not have a common exit.

PERFORM Statement

The PERFORM statement executes a procedure, or group of procedures as established

by the THROUGH phrase, one time. When execution completes, control passes to the

statement following the PERFORM statement.

proc-1 and proc-2

are the procedure paragraphs or sections to be executed.

The following example illustrates a PERFORM of one paragraph:

IF report-a

PERFORM do-report-a.

The following example illustrates a PERFORM of several paragraphs:

IF reports

PERFORM do-reports THRU do-reports-exit.

do-reports.

(several paragraphs to create the reports)

do-reports-exit.

EXIT.

PERFORM proc-1 [ { THROUGH } proc-2 ]

[ { THRU } ]