How To Use REDUCE Operator in ABAP 7.4/7.5 New Syntax

REDUCE OPERATOR IN ABAP

Used to calculate total and subtotals.

Syntax:

REDUCE <type>( INIT ... FOR... THEN... UNTIL... NEXT... )

INIT     - Initial value
FOR     - Initialize iteration
THEN  - Increment value
UNTIL - Iteration End condition
NEXT  - Operation

How To Use REDUCE Operator in ABAP 7.4/7.5 New Syntax

Example 1

To find the sum of first 10 numbers. sum of first 10 numbers.

DATA(v1) = REDUCE i( INIT sum = 0 FOR i = 1 THEN i + 1 UNTIL i > 10 NEXT sum = sum + i ).

Even if THEN keyword is not specified the default increment will happen with 1

DATA(v1) = REDUCE i( INIT sum = 0 FOR i = 1 UNTIL i > 10 NEXT sum = sum + i ).

WRITE:/ v1.

Example 2 :

Using String

DATA(v2) = REDUCE string( INIT text = `Count up:` FOR i = 1 THEN i + 1 UNTIL i > 10 NEXT text = text && | { i } | ).

DATA(v3) = REDUCE string( INIT text = `Count down:` FOR i = 10 THEN i - 1 UNTIL i < 1 NEXT text = text && | { i } | ).

WRITE:/ v2.
WRITE:/ v3.

Output:

Count up: 1  2  3  4  5  6  7  8  9  10
Count down: 10  9  8  7  6  5  4  3  2  1

Example 3

Calculate Sum in internal table

Code:

REPORT ztest_program.

TYPES: BEGIN OF ty_emp,
         empname TYPE string,
         role    TYPE string,
         salary  TYPE i,
       END OF ty_emp.

DATA: it_employees TYPE TABLE OF ty_emp.

DATA: lv_tot_salary TYPE i.

*-- Populate Internal Table
it_employees = VALUE #( ( empname = 'John'   role = 'Analyst'    salary = '10000' )
                        ( empname = 'Steve'  role = 'Sr Analyst' salary = '15000' )
                        ( empname = 'Marcus' role = 'Jr Analyst' salary = '7000'  )
                        ( empname = 'Surya'  role = 'Jr Analyst' salary = '7000'  )
                       ).

*-- TOTAL CALCULATION

*--- Before ABAP 7.4/7.5
*LOOP AT it_employees INTO DATA(wa_employees).
*
*  lv_tot_salary = lv_tot_salary + wa_employees-salary.
*ENDLOOP.

*--- After ABAP 7.4/7.5
lv_tot_salary = REDUCE i( INIT total = 0 FOR wa_employees IN it_employees NEXT total = total + wa_employees-salary ).

WRITE:/ 'Total Salary:', lv_tot_salary.

Output:

Total Salary:39000

The work area is local to the reduce expression and declaration is not required.

If the requirement is to find the sum with particular condition. lets say role = 'Jr Analyst' then insert WHERE condition.

lv_tot_salary = REDUCE i( INIT total = 0 FOR wa_employees IN it_employees WHERE ( role = = 'Jr Analyst' ) NEXT total = total + wa_employees-salary ).

REDUCE in Nested loops

Read this: https://blogs.sap.com/2017/05/25/replace-the-loop-for-reduce-operator/