Calculate a result in a string

[Former Member]

I have string, which contains '5 * 7'.

How can I get the result into my integer variable?

Any ideas.

Thanks

Rene

[suresh_datti]

try this

data : w_result type i,
       w_string1 type string,
       w_string2 type string,
       w_string3 type string.

w_string1 = '5*7'.
split w_string1 at '*' into w_string2 w_string3.
w_result = w_string2 * w_string3.

Regards,

Suresh Datti

[Former Member]

If you know that the * character is the seperating character you can use this..

DATA str(12) VALUE '1 * 3'.
DATA str1(10).
DATA str2(10).

SPLIT str AT '*' into str1 str2.

DATA i_1 TYPE i.
DATA i_2 TYPE i.

i_1 = str1.
i_2 = str2.

WRITE: i_1, i_2.

[Former Member]

If all you know is that there is a valid computation in the string, you could use the "GENERATE" statement to put it into a program and execute it.

Rob

[former_member186741]

You could do this sort of thing:

REPORT znrw_calculator MESSAGE-ID z1.

PARAMETERS: p_code1(20) LOWER CASE.

DATA t_source_tab(72) OCCURS 0 WITH HEADER LINE.

DATA g_program_name LIKE sy-repid.

DATA g_syntax_message(128).

DATA g_line_no TYPE i.

DATA var TYPE p.

AT SELECTION-SCREEN.

PERFORM check_dynamic_abap.

START-OF-SELECTION.

PERFORM do_the_business IN PROGRAM (g_program_name) CHANGING var .

WRITE:/ p_code1 NO-GAP,'=' NO-GAP,var.

&----

---

*& Form CHECK_DYNAMIC_ABAP

&----

---

FORM check_dynamic_abap.

DATA t_abap(80) OCCURS 0 WITH HEADER LINE.

*set up a dynamic program

REFRESH t_source_tab.

APPEND 'REPORT' TO t_source_tab.

APPEND sy-repid TO t_source_tab.

APPEND '.' TO t_source_tab.

APPEND 'FORM do_the_business changing var type p.' TO t_source_tab.

APPEND 'var =' TO t_source_tab.

append p_code1 to t_source_tab.

APPEND '.' TO t_source_tab.

APPEND 'ENDFORM.' TO t_source_tab.

*Generate the dynamic program so that the form can be used subsequently.

GENERATE SUBROUTINE POOL t_source_tab NAME g_program_name

MESSAGE g_syntax_message LINE g_line_no.

IF sy-subrc <> 0.

MESSAGE e999 WITH g_syntax_message.

ENDIF.

ENDFORM. . "CHECK_DYNAMIC_ABAP

[Former Member]

Hi

I am in the processs of writting my own code to evaluate the string, if it is any type of formular with + - / * and ( ) .

But I have also looked in to the generate subroutine pool solutions as your are proposing.

I was looking for something better then these two options.

Have you an idea how fast the generate subroutine pool solution would be.

I have to do this for a lot of records and need a very fast solution.

Thanks

[Former Member]

If all of your records can be generated at once in one subroutine pool, it shouldn't be too bad; but if you have to generate a separate pool for each statement, it would be quicker to parse it yourself (although it mnight be quite a programming challenge).

Rob

[former_member186741]

the generation method is very elegant but is really best suited to an on-line validation of a free-from string. If you have thousands of records I think the best solution will be the long-winded approach, this will give you better error handling capability too.

[Former Member]

HI rene,

1. There is no direct way

to do such computations

which are available as a string.

2. by doing some hard coding,

we can manage to calculatge 5 * 7.

3. But if the formula is a little more

complex

eg. 2 *5 + (6 / 3 ) * 5.5 - 9

then, things go for a toss !

regards,

amit m.

[Former Member]

Rene,

Here is some example logic from the suggestions stated above, and more complex, also stated above, computations get interesting. Good luck.

Regards,

Terry

REPORT Y_CALCULATE_STRING_RESULT .

DATA: MYSTRING(30),
      VALUE1(10),
      VALUE2(10),
      RESULT(10),
      CALC_ADD VALUE '+',
      CALC_SUBTRACT VALUE '-',
      CALC_MULTIPLY VALUE '*',
      CALC_DIVIDE VALUE '/'.

MYSTRING = '5 * 7'.
*MYSTRING = '5 + 7'.
*MYSTRING = '5 - 7'.
*MYSTRING = '5 / 7'.

SPLIT MYSTRING AT CALC_ADD INTO VALUE1 VALUE2.

IF NOT VALUE2 IS INITIAL.
  CONDENSE: VALUE1, VALUE2.
  RESULT = VALUE1 + VALUE2.
  CONDENSE RESULT.
ENDIF.

SPLIT MYSTRING AT CALC_SUBTRACT INTO VALUE1 VALUE2.

IF NOT VALUE2 IS INITIAL.
  CONDENSE: VALUE1, VALUE2.
  RESULT = VALUE1 - VALUE2.
  CONDENSE RESULT.
ENDIF.

SPLIT MYSTRING AT CALC_MULTIPLY INTO VALUE1 VALUE2.

IF NOT VALUE2 IS INITIAL.
  CONDENSE: VALUE1, VALUE2.
  RESULT = VALUE1 * VALUE2.
  CONDENSE RESULT.
ENDIF.

SPLIT MYSTRING AT CALC_DIVIDE INTO VALUE1 VALUE2.

IF NOT VALUE2 IS INITIAL.
  CONDENSE: VALUE1, VALUE2.
  RESULT = VALUE1 / VALUE2.
  CONDENSE RESULT.
ENDIF.

WRITE:/ 'The result of', MYSTRING,
      / 'is', RESULT.

[Former Member]

I have done tests in both directions. With my own code and generated code. The own code is clearly faster if you need to generate serveral performs.

[former_member186741]

Another option would be to use a macro.

eg look at this program.

REPORT ZMACRO.

DATA: RESULT TYPE I,

N1 TYPE I VALUE 5,

N2 TYPE I VALUE 6.

DEFINE OPERATION.

RESULT = &1 &2 &3.

OUTPUT &1 &2 &3 RESULT.

END-OF-DEFINITION.

DEFINE OUTPUT.

WRITE: / 'The result of &1 &2 &3 is', &4.

END-OF-DEFINITION.

OPERATION 4 + 3.

OPERATION 2 ** 7.

OPERATION N2 - N1.

The produces the following output:

The result of 4 + 3 is 7

The result of 2 ** 7 is 128

The result of N2 - N1 is 1