Perform Until Statement - COBOL Statements

Purpose

The PERFORM UNTIL statement provides iteration support, allowing a section of code to be executed multiple times.

Syntax

COBOL Metalanguage

perform-until-statement



PERFORM
[
paragraph-name
[{
THROUGH
}
paragraph-name
]]


THRU


[
WITH TEST
{
BEFORE
}
]


AFTER


UNTIL condition

[
statement-block

END-PERFORM ]

PERFORM	[	paragraph-name	[{	THROUGH	}	paragraph-name	]]
THRU
	[	WITH TEST	{	BEFORE	}	]
AFTER
	UNTIL condition
[	statement-block
END-PERFORM ]

Semantics

The body of the loop (iteration) is either a statement block or a paragraph range; one but not both must be specified.
If TEST BEFORE is specified, the UNTIL condition will be tested before each execution of the body. This means that the body will be executed 0 or more times.
If TEST AFTER is specified, the UNTIL condition will be tested after each execution of the body. This means that the body will be executed 1 or more times.
TEST BEFORE is the default.

External Links

University of Limerick	COBOL Iteration Constructs
University of Northern Iowa	Compaq COBOL Reference Manual