COBOL supress last number while summing two decimal numbers - cobol

Question

According to the COBOL code below when I try to sum WS-NUM1 with WS-NUM2, COBOL seems to supress the last number. For example: variable WS-NUM1 and WS-NUM2 are 10.15, I get 20.20 as result but expected 20.30. What's wrong?
WS-NUM1 PIC 9(2)V99.
WS-NUM2 PIC 9(2)V99.
WS-RESULTADO PIC 9(2)V99.
DISPLAY "Enter the first number:"
ACCEPT WS-NUM1.
DISPLAY "Enter the second number:"
ACCEPT WS-NUM2.
COMPUTE WS-RESULTADO = WS-NUM1 + WS-NUM2.
Thanks in advance.

Answer 1

PIC 9(2)v99 defines a variable with an implied decimal place not a real one. You're trying to enter data containing a decimal point and it's not working because you have to strip out the '.' to get the numeric part of your data to properly fit in the 4 bytes that your working storage area occupies.
PROGRAM-ID. ADD2.
data division.
working-storage section.
01 ws-num-input pic x(5).
01 WS-NUM1 PIC 9(2)V99 value 0.
01 redefines ws-num1.
05 ws-high-num pic 99.
05 ws-low-num pic 99.
01 WS-NUM2 PIC 9(2)V99 value 0.
01 redefines ws-num2.
05 ws-high-num2 pic 99.
05 ws-low-num2 pic 99.
01 WS-RESULTADO PIC 9(2)V99.
PROCEDURE DIVISION.
DISPLAY "Enter the first number:"
*
accept ws-num-input
unstring ws-num-input delimited by '.'
into ws-high-num, ws-low-num
DISPLAY "Enter the second number:"
accept ws-num-input
unstring ws-num-input delimited by '.'
into ws-high-num2, ws-low-num2
*
COMPUTE WS-RESULTADO = WS-NUM1 + WS-NUM2.
DISPLAY WS-RESULTADO
STOP RUN
.
This is just a simple demonstration. In a real world application you would have to insure much more robust edits to ensure that valid numeric data was entered.

Answer 2

If I declare it like this
01 WS-NUM1 PIC 9(2)V99.
01 WS-NUM2 PIC 9(2)V99.
01 WS-RESULTADO PIC 9(2)V99.
and define and sum them up like this
SET WS-NUM1 TO 10.15.
SET WS-NUM2 TO 10.15.
COMPUTE WS-RESULTADO = WS-NUM1 + WS-NUM2.
DISPLAY WS-RESULTADO.
I get the expected result of 20.30.

Answer 3

This looks like a job for a special type of PICture : Edited picture
Indeed you seem to know about the vanilla PICture clause (I'm writing PICture because as you may know it you can either write PIC or PICTURE).
A vanilla number PIC contains only 4 different symbols (and the parentheses and numbers in order to repeat some of the symbols)
9 : Represents a digit. You can repeat by using a number between parentheses like said before.
S : Means that the number is signed
V : Show the position of the implicit decimal point
P : I've been told that it exists but I honestly never found it in the codebase of my workplace. Its another kind of decimal point used for scaling factors but I don't know much about it.
But there are other symbols.
If you use theses other mysterious symbols the numeric PIC becomes an edited numeric PIC. As its name says, an edited PICture is made to be shown. It will allow you to format your numbers for better presentation or to receive number formatted for human reading.
Once edited, you cannot use it to make computations so you will have to transfer from edited to vanilla to perform computations on the latter. And you move from vanilla to edited in order to display your results.
So now I shall reveal some of these mysterious symbols :
B : Insert a blank at the place it is put
0 : Insert a zero at the place it is put
. : Insert the decimal point at the place it is put
: Insert a + if the number is positive and a - if the number is negative
Z : Acts like a 9 if the digits it represents has a value different than 0. Acts like a blank if the digits has the value of 0.
To my knowledge there are also : / , CR DB * $ -
You can look up for it on the internet. They really show the accountant essence of cobol.
For your problems we are really interested by the "." which will allow us to take into account the decimal point you have the write when you type down your input.
For a bonus I will also use Z which will make your result looks like 2.37 instead of 02.37 if the number is less than ten.
Note that you cannot use the repeating pattern with parenthesis ( 9(03) for instance) when describing an edited picture ! Each digits has to represented explicitly
IDENTIFICATION DIVISION.
PROGRAM-ID. EDITCOMP.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 WS-NUM1-EDITED PIC 99.99.
01 WS-NUM2-EDITED PIC 99.99.
01 WS-NUM1-CALC PIC 9(2)V99.
01 WS-NUM2-CALC PIC 9(2)V99.
01 WS-RESULTADO-EDITED PIC Z9.99.
PROCEDURE DIVISION.
ACCEPT WS-NUM1-EDITED.
ACCEPT WS-NUM2-EDITED.
MOVE WS-NUM1-EDITED TO WS-NUM1-CALC.
MOVE WS-NUM2-EDITED TO WS-NUM2-CALC.
COMPUTE WS-RESULTADO-EDITED = WS-NUM1-CALC + WS-NUM2-CALC.
DISPLAY WS-RESULTADO-EDITED.
STOP RUN.
You should note that there also exist edited alphanumeric picture. You can insert Blank (B), zeroes (0) or / (/) in it.