topic Re: Convert a arithmetic expression into computed value in Application Development and Automation Discussions

Convert a arithmetic expression into computed value

jaiprasad_naidu5 — Wed, 13 Nov 2013 14:57:43 GMT

Dear All,

I have a requirement of converting a arithmetic expression into a computed value.

Example : Variable of type string will have expression as : '123 + 456 + 2'.

I want the result as 581. I tried various methods but it doesn't work.

Can any help in achieving this.

Thank you,

jp.

Re: Convert a arithmetic expression into computed value

vladimir_erakovic — Wed, 13 Nov 2013 15:11:09 GMT

Hi Jaiprasad,

Try like this:

DATA: val TYPE string.

DATA: v1(4) TYPE n,

v2(4) TYPE n,

v3(4) TYPE n,

v4(4) TYPE n.

val = '50 + 35 + 24'.

SPLIT val AT ' + ' INTO v1 v2 v3.

v4 = v1 + v2 + v3.

Adjust to your needs but that's one way.

Regards,

Vladimir

Re: Convert a arithmetic expression into computed value

UweFetzer_se38 — Wed, 13 Nov 2013 15:42:43 GMT

Secret hint: have a look at function module "FORMULA_EVALUATION".

Re: Convert a arithmetic expression into computed value

Former Member — Wed, 13 Nov 2013 16:05:23 GMT

Hi,

you can see this example

   DATA va_string TYPE string VALUE '123 + 456 + 2'.

TYPES: BEGIN OF ty_calc,
        v1(5) TYPE n,
         END OF ty_calc.

DATA t_string TYPE TABLE OF ty_calc WITH HEADER LINE.

DATA va_sum(5) TYPE n.

START-OF-SELECTION.

REFRESH t_string.
CLEAR: t_string, va_sum.

SPLIT va_string AT '+' INTO TABLE t_string.

LOOP AT t_string.
IF sy-tabix = 1..
    va_sum = t_string-v1.
ELSE.
    va_sum = va_sum + t_string-v1.
ENDIF.

ENDLOOP.

WRITE va_sum.

Re: Convert a arithmetic expression into computed value

SuhaSaha — Wed, 13 Nov 2013 16:50:28 GMT

I would rather use the "internally released" EVAL_FORMULA

My 2 cents ...

Re: Convert a arithmetic expression into computed value

Former Member — Wed, 13 Nov 2013 17:39:26 GMT

Hello

i have a doubt, if i change the string input by...

val = ' 50 * 30 - 20 + 30 / 10 * ( 1 + 2 ) * 5 ' .

then how we will use your concept.

Re: Convert a arithmetic expression into computed value

vladimir_erakovic — Wed, 13 Nov 2013 18:01:23 GMT

Hello Chandra,

Then we will change the concept

I don't know. This was for example in question. For that kind of equations it should be some algorithm..

Do you have some idea?

Re: Convert a arithmetic expression into computed value

Former Member — Wed, 13 Nov 2013 18:04:12 GMT

No dear, I wasn't testing you, i am really looking for some logic but i think in that case we need to use some postfix/ prefix algorithm.

Re: Convert a arithmetic expression into computed value

SuhaSaha — Wed, 13 Nov 2013 20:08:36 GMT

i am really looking for some logic but i think in that case we need to use some postfix/ prefix algorithm.

Unless you want to re-invent the wheel ...

Re: Convert a arithmetic expression into computed value

jaiprasad_naidu5 — Thu, 14 Nov 2013 04:41:19 GMT

Hi,

As Mr.Chandra said the expression would change dynamically depending upon the requirement. Few examples I would give :

1. (123 + 456) / 654

2. (123 * 12) + 123 - 567

regards,

Re: Convert a arithmetic expression into computed value

jaiprasad_naidu5 — Thu, 14 Nov 2013 04:52:52 GMT

Hi Ivan,

Thanks for your reply. You logic perfectly works in case it is only addition. If the expression changes dynamically with different operators then how do we address it.

Example :

1. (123 + 456) / 654

2. (123 * 12) + 123 - 567

regards,

Re: Convert a arithmetic expression into computed value

Former Member — Thu, 14 Nov 2013 06:09:36 GMT

Hi,

You can use this FM to remove the special characters

ES_REMOVE_SPECIAL_CHARACTER

Then you can use split command.

Code :

DATA : exp TYPE CHAR100 VALUE '(123 * 12) + 123 - 567 / 234',
str TYPE char100.

TYPES : BEGIN OF ty_num,
num TYPE char10,
END OF ty_num.

DATA : i_tab TYPE TABLE OF ty_num,
wa_tab TYPE ty_num.

START-OF-SELECTION.
CALL FUNCTION 'ES_REMOVE_SPECIAL_CHARACTER'
EXPORTING
text1 = exp
IMPORTING
CORR_STRING = str.

SPLIT str At space INTO TABLE i_tab.

LOOP AT i_tab INTO wa_tab.
If wa_tab-num eq space.
DELETE i_tab INDEX sy-tabix.
ENDIF.
ENDLOOP.

Or,

START-OF-SELECTION.
REPLACE all OCCURRENCES OF regex '[^\d]' in exp WITH '/'.

SPLIT exp At '/' INTO TABLE i_tab.

Loop again.

Hope this helps.

Regards

Re: Convert a arithmetic expression into computed value

Former Member — Thu, 14 Nov 2013 06:15:19 GMT

Hi,

There is a function module available for the purpose as mentioned by Suhas Saha.

> First check for the validity of the syntax of equation using FM

CHECK_FORMULA

> If validated then compute the equation using FM

EVAL_FORMULA

Regards,

Ashish Rawat

Re: Convert a arithmetic expression into computed value

former_member209120 — Thu, 14 Nov 2013 07:03:00 GMT

Hi Jaiprasad Naidu

Simple

Try like this

Data : var_final type p,
        v_len type i.

Parameter : var type string.

Replace all OCCURRENCES OF '(' in var with ' (?'.
Replace all OCCURRENCES OF ')' in var with ' )?'.
Replace all OCCURRENCES OF '/' in var with ' /?'.
Replace all OCCURRENCES OF '+' in var with ' +?'.
Replace all OCCURRENCES OF '*' in var with ' *?'.
Replace all OCCURRENCES OF '-' in var with ' -?'.

v_len = strlen( var ).

Do v_len times.
replace '?' WITH SPACE INTO var.
enddo.
shift var LEFT DELETING LEADING SPACE.

CALL FUNCTION 'EVAL_FORMULA'
   EXPORTING
*   DEGREES                       = ' '
     formula                       = var
*   PROGRAM                       = ' '
*   ROUTINE                       = ' '
*   UNIT_OF_MEASURE               = ' '
*   NO_EXISTENCE_CHECK            = ' '
IMPORTING
    VALUE                         = var_final
* EXCEPTIONS
*   DIVISION_BY_ZERO              = 1
*   EXP_ERROR                     = 2
*   FORMULA_TABLE_NOT_VALID       = 3
*   INVALID_EXPRESSION            = 4
*   INVALID_VALUE                 = 5
*   LOG_ERROR                     = 6
*   PARAMETER_ERROR               = 7
*   SQRT_ERROR                    = 8
*   UNITS_NOT_VALID               = 9
*   MISSING_PARAMETER             = 10
*   OTHERS                        = 11
           .
IF sy-subrc <> 0.
* MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
*         WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.

Write : / var_final.