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luttapi
New User
Joined: 05 Jun 2007
Posts: 24
Location: kerala
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I have an internal table in cobol declared as follows
01 ws-inter-table
03 ws-table-struct occurs 100 times.
I have moved values into this table. And suppose I am accessing the ws-table-struct[0] what would be it contain? Can I refer table elements like this. |
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dick scherrer
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Joined: 23 Nov 2006
Posts: 19244
Location: Inside the Matrix
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Hello,
It is not clear what you are asking. . .
"ws-table-struct[0]" is invalid.
You can use a numeric literal for a subscript but you would use "ws-table-struct(n)" and n should be > zero and < 101. |
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Escapa
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Joined: 16 Feb 2007
Posts: 1399
Location: IL, USA
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Robert Sample
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Joined: 06 Jun 2008
Posts: 8697
Location: Dubuque, Iowa, USA
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The answer to your question is ... it depends.
If the compiler option SSRANGE was set when the program is compiled, COBOL checks for and does not allow any reference to an element of the table outside the defined range (1 to 100 in your case). If you attempt to do so, you get an error message.
If this compiler option was not set, then accessing a table element outside the defined range may -- and may not -- access data within your program or other memory locations. Typically such memory access is not good, may cause abends, but is not prevented by the system. |
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ridgewalker58
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Joined: 26 Sep 2008
Posts: 51
Location: New York
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As Mr. Sample has stated -- you would be able to access the space that preceeds the table by using a SUBSCRIPT with a value of ZERO.
Example: 01 WS-HOLD-AREA PIC X(02) VALUE SPACES.
01 WS-SUB1 PIC 9(04) COMP VALUE ZERO.
01 WS-TEST-FIELD PIC X(05) VALUE 'ABCDE'.
01 WS-TABLE.
05 WS-TBL-ENTRIES OCCUR 20 TIMES.
10 WS-TBL-FLD1 PIC X(03).
10 WS-TBL-FLD2 PIC X(02).
MOVE WS-TBL-FLD2 (WS-SUB1) TO WS-HOLD-AREA.
>>>>> WS-HOLD-AREA WOULD NOW CONTAIN 'DE'
>>>>> YOU HAVE MOVED 2 BYTES THAT PRECEED THE TABLE TO
WS-HOLD-AREA |
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dick scherrer
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Joined: 23 Nov 2006
Posts: 19244
Location: Inside the Matrix
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Hello,
| Quote: |
| >>>>> WS-HOLD-AREA WOULD NOW CONTAIN 'DE' |
Did you test this?
While the code may not abend, WS-HOLD-AREA may also not have DE (unless the compiler has been changed and i didn't get the memo  ) |
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Terry Heinze
JCL Moderator
Joined: 14 Jul 2008
Posts: 1249
Location: Richfield, MN, USA
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| Quote: |
| WS-HOLD-AREA WOULD NOW CONTAIN 'DE' |
As Dick indicates, if the 2 bytes before the start of WS-TABLE contain 'DE' after the MOVE, it would be a miraculous coincidence. For one thing, since 01 levels are double word aligned, there are 3 bytes of data that occur after 'ABCDE' that probably contain X'000000' with the Enterprise compiler, but there's no guarantee of that. For another, there's no guarantee that WS-TABLE immediately follows the 8 bytes where WS-TEST-FIELD begins. This information is available in the COBOL Language Reference manual. |
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