Editing PL/I (section)

===GO TO with a non-fixed target===
PL/I has counterparts for COBOL and FORTRAN's specialized GO TO statements.

Syntax for both COBOL and FORTRAN exist for coding two special two types of {{mono|GO TO}}, each of which has a target that is not always the same.
* {{tt|ALTER}} (COBOL), {{tt|ASSIGN}} (FORTRAN):
** {{code|ALTER paragraph_name_xxx TO PROCEED TO para_name_zzz|cobolfree}} (“altered go to”).<ref name=COB.IBM>{{cite web
 |url=https://www.ibm.com/support/knowledgecenter/en/SS6SG3_4.2.0/com.ibm.entcobol.doc_4.2/PGandLR/ref/rlpsalte.htm
 |title=ALTER statement|website=[[IBM]] |date=24 September 2021}}</ref>
**: There are other/helpful restrictions on these, especially "in programs ... {{tt|RECURSIVE}} attribute, in methods, or .. {{tt|THREAD}} option."<ref name=COB.IBM/>
** {{code|ASSIGN 1860 TO IGOTTAGO|fortran}} (“assigned go to”)<ref name=ONLY2THESE>{{cite web
 |url=https://docs.oracle.com/cd/E19957-01/805-4939/6j4m0vn9j/index.html
 |title=GO TO (Assigned)}}</ref><br />{{code|GO TO IGOTTAGO}}
**: One enhancement, which adds built-in documentation, is {{code|GO TO IGOTTAGO (1860, 1914, 1939)}}
**:: (which restricts the variable's value to "one of the labels in the list.")<ref name=ONLY2THESE/>
* {{tt|GO TO}} ... based on a variable's subscript-like value.
** {{code|GO TO (1914, 1939, 2140), MYCHOICE}} (“computed go to”)<ref>{{cite web
 |url=https://docs.oracle.com/cd/E19957-01/805-4939/6j4m0vn9l/index.html
 |title=GO TO (Computed)}}</ref>
** {{code|GO TO para_One para_Two para_Three DEPENDING ON IDECIDE|cobol}} (“go to depending on”).<ref>{{cite web
 |url=https://www.tutorialride.com/cobol/go-to-statement-in-cobol.htm
 |title=GO TO Statement in COBOL}}</ref>

PL/I has statement label variables (with the {{tt|LABEL}} attribute), which can store the value of a statement label, and later be used in a {{tt|GOTO}} statement.<ref>{{cite book
 |title=Digital Research PL/I Language Programmer's Guide
 |page=103}}</ref><ref name="gc33-0009-4"/>{{rp|54}}<ref name="gc33-0009-4"/>{{rp|23}}
<pre>
LABL1: ....
.
.
LABL2: ...
.
.
.
MY_DEST = LABL1;
.
GO TO MY_DEST;
</pre>

The programmer can also create an array of static label constants by subscripting the statement labels.
 GO TO HERE(LUCKY_NUMBER); /* minus 1, zero, or ... */

 HERE(-1): PUT LIST ("I O U"); GO TO Lottery;
 HERE(0): PUT LIST ("No Cash"); GO TO Lottery;
 HERE(1): PUT LIST ("Dollar Bill"); GO TO Lottery;
 HERE(2): PUT LIST ("TWO DOLLARS"); GO TO Lottery;

Statement label variables can be passed to called procedures, and used to return to a different statement in the calling routine.