WHILE Initiate WHILE block

Domain: PROCEDURE

Command description

WHILE initiates a WHILE block, i.e. a WHILE loop: execution of the command sequence within the WHILE block is repeated as long as the condition specified in the WHILE command is met. If the condition is not met, the loop is terminated and procedure execution resumes with the command following the terminating END-WHILE command. (See the remarks on control structures in section “WHILE block” (Defining loops ) for more information.)

Expressions are replaced in the operand only when entering the WHILE loop, but not each time the loop is executed.

Format

WHILE

CONDITION = <text 0..1800 with-low bool-expr>

Operands

CONDITION = <text 0..1800 with-low bool-expr>
Logical expression as the condition for re-executing the commands in the WHILE loop (see chapter “Expressions” for information on logical expressions).

Command return codes

(SC2)	SC1	Maincode	Meaning
	0	CMD0001	No error
	1	CMD0202	Syntax error
	1	SDP0118	Command in false context
	1	SDP0139	Back branch limit reached
	1	SDP0223	Incorrect environment
	3	CMD2203	Incorrect syntax file
	32	CMD0221	System error (internal error)
	64	SDP0091	Semantic error
	130	SDP0099	No further address space available

Example

/ "Reduce list variable LIST-A to last 250 elements"
/WHILE (SIZE ('LIST-A') > 250)
/  FREE-VARIABLE LISTE-A#
/END-WHILE