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ashok.gkyadav
New User
Joined: 05 Sep 2006
Posts: 6
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What would be the result of the following?
05 WS-A PIC 9(3).
05 WS-B REDEFINES WS-A PIC X(5).
Move 999 to WS-A.
Display WS-B. |
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muthuvel
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Joined: 29 Nov 2005
Posts: 217
Location: Canada
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WS-B will have 999
Please search the forum before you make a post. |
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Phrzby Phil
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Joined: 31 Oct 2006
Posts: 1042
Location: Richmond, Virginia
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| I would expect a compile error as WS-B is longer than WS-A. |
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muthuvel
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Joined: 29 Nov 2005
Posts: 217
Location: Canada
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Phil,
I tried it out and i got the value 999 moved to WS-B.
REDEFINING the varaible longer or shorter will not give a compiler error.It is possible for truncation of data if the redefined variable is shorter. |
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Phrzby Phil
Senior Member
Joined: 31 Oct 2006
Posts: 1042
Location: Richmond, Virginia
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I see I was wrong about the compiler error.
However, notwithstanding the lack of a compile warning/error, you really don't want the redefining variable to be longer.
Above, the actual value of WS-B is:
bytes 1-3 = '999'
bytes 4-5 = x'00'
Here's the hex display:
999
FFF00
99900
This test:
IF WS-B = '999'
DISPLAY 'EQUALS 999'
ELSE
DISPLAY 'NOT EQUALS 999'
END-IF.
produces this output:
NOT EQUALS 999
because the compare of '999' against the X(5) field is trying to match '999' blank-blank. |
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William Thompson
Global Moderator
Joined: 18 Nov 2006
Posts: 3156
Location: Tucson AZ
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| muthuvel wrote: |
| I tried it out and i got the value 999 moved to WS-B. |
No, not quite, if you had done a display '*' WS-B '*' you would have seen "*999??* where the ? is whatever was previously in WS-B.
| Quote: |
| REDEFINING the variable longer or shorter will not give a compiler error.It is possible for truncation of data if the redefined variable is shorter. |
No, not quite, it is more dependent upon the compiler. Either way you will never get truncation; if the compiler can't handle it, it will fail compile; if the compiler can handle it, it will reserve the extra space after the redefined data to cover for the longer redefining data. |
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muthuvel
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Joined: 29 Nov 2005
Posts: 217
Location: Canada
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Phil and William,
Thanks  |
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