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Diff between HIGH-VALUES and SPACES
- Thread starter sriganti
- Start date
Hi sriganti,
The ASCII ( decimal value of SPACE is 32.
The decimal value of HIGH-VALUES is usually 255 (the highest value that can fit in one byte).
SPACE is handy when you want to initialize a string (PIC X) to 'nothing'. Of course, value 'space' could be a valid value in given cases. By the way, LOW-VALUES (ASCII decimal value 0) is commonly used to initialize numeric fields to 'nothing'.
If you use the COBOL verb INITIALIZE on a group level, spaces will be moved to alphanumeric fields and LOW-VALUES (binary zeroes) will be moved to numeric fields.
HIGH-VALUES is handy when you want to initialize a field to the highest possible value - for comparisons with other fields, for example.
Dimandja
The ASCII ( decimal value of SPACE is 32.
The decimal value of HIGH-VALUES is usually 255 (the highest value that can fit in one byte).
SPACE is handy when you want to initialize a string (PIC X) to 'nothing'. Of course, value 'space' could be a valid value in given cases. By the way, LOW-VALUES (ASCII decimal value 0) is commonly used to initialize numeric fields to 'nothing'.
If you use the COBOL verb INITIALIZE on a group level, spaces will be moved to alphanumeric fields and LOW-VALUES (binary zeroes) will be moved to numeric fields.
HIGH-VALUES is handy when you want to initialize a field to the highest possible value - for comparisons with other fields, for example.
Dimandja
A bit of trivia for the newbei COBOL mainframers out there:
There's another way to set a field to X'FF', in this case a COMP field. You'll see this done in CICS to tell BMS where to position the cursor on the screen.
You move -1 to the length field associated with the data field you desire to have the cursor positioned to. The length field is defined as PIC S9(04) COMP in the symbolic map.
DB2 uses the same approach to mark a DB2 column as null by moving -1 to the column's null indicator field.
If reference modification was available then, I think they might have opted for it instead of the move -1 technique.
In both cases the move of the -1 to the field changes the field to all X'FF' as a result of the 2s-comlement arithmetic used to populate the field.
For completeness I guess I should also mention the "move all X'FF'" approach.
Jack
There's another way to set a field to X'FF', in this case a COMP field. You'll see this done in CICS to tell BMS where to position the cursor on the screen.
You move -1 to the length field associated with the data field you desire to have the cursor positioned to. The length field is defined as PIC S9(04) COMP in the symbolic map.
DB2 uses the same approach to mark a DB2 column as null by moving -1 to the column's null indicator field.
If reference modification was available then, I think they might have opted for it instead of the move -1 technique.
In both cases the move of the -1 to the field changes the field to all X'FF' as a result of the 2s-comlement arithmetic used to populate the field.
For completeness I guess I should also mention the "move all X'FF'" approach.
Jack
Hi Hugh,
One way is to create a table of days, e.g.:
In your procedure division, isolate the month of the date you're using and verify that it is numeric and between 1 and 12 inclusive.
Then determine if the year is a leap year. If it is add 1 to the Feb value in the table. (Hint- use the month# of Feb as a subscript).
Now, use the month# of your date as a subscript in the MOVE stmt that will move the # of days from the table to your receiving field.
One way is to create a table of days, e.g.:
Code:
01 days-tbl value
312831303130313130313031. *==> I think you can do this if not use redefines.
05 day-entry pic 9(002)
occurs 12.
01 month-nbr pic 9(002). *==> this is the subscriptThen determine if the year is a leap year. If it is add 1 to the Feb value in the table. (Hint- use the month# of Feb as a subscript).
Now, use the month# of your date as a subscript in the MOVE stmt that will move the # of days from the table to your receiving field.
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