SAP-ABAP-740新语法解析中文版六：REDUCE运算符，迭代运算

REDUCE 循环迭代构造数据可以计算以下数据

1.统计表中有多少行符合要求的数据？

2.循环累计总金额

3.循环拼接字符串

具体代码如下

 """"准备测试数据 DATA lv_numb TYPE i . SELECT  ryear  ,racct     , rbukrs   , tslvt    ,         tsl01  ,tsl02     , tsl03    , tsl04    ,         tsl05  ,tsl06     , tsl07    , tsl08    ,         tsl09  ,tsl10     , tsl11    , tsl12    ,         tsl13  ,tsl14     , tsl15    , tsl16   FROM  faglflext   WHERE rbukrs = '1000'   AND   ryear  = '2020'   AND   racct  = '8035000001'   INTO TABLE @DATA(lt_fag)   UP TO 10 ROWS. IF lt_fag[] IS INITIAL. "   DO 10 TIMES.     APPEND INITIAL LINE TO lt_fag ASSIGNING FIELD-SYMBOL() .     DO 20 TIMES.       ASSIGN COMPONENT sy-index OF STRUCTURE  TO FIELD-SYMBOL() .       CASE sy-index.         WHEN 1.            = '2020'.         WHEN 2.            = '8035000001'.         WHEN 3.            = '1000'.         WHEN 4.            = '0'.         WHEN OTHERS.            =    lv_numb .       ENDCASE.       lv_numb = lv_numb   1 .     ENDDO.   ENDDO. ENDIF.  ""统计表中有多少行符合要求的数据？ DATA(lv_lines) = REDUCE i( INIT x = 0 FOR wa1 IN lt_fag WHERE ( rbukrs = '1000' ) NEXT x = x   1 ). ""循环累加计算总金额 DATA(lv_sum) = REDUCE wertv12( INIT x = 0 FOR wa2 IN lt_fag NEXT x = x   wa2-tslvt   wa2-tsl01   wa2-tsl02  ). ""循环拼接字符串 DATA(lv_string) = REDUCE string( INIT  tex = `递增数据：` FOR n = 1 THEN N   1 UNTIL n > 9 NEXT tex = tex && n   ). 

REDUCE句子只能计算一个值，类型紧随其后REDUCE基本数据类型和数据元素可以定义类型，INIT接变量后，初始化数据，for连接循环数据，可循环表，也可累积循环，循环表正常loop循环相同，循环每一行存储在工作区域，然后进行计算，计循环for控制数据，then修改每个循环一次，until作为跳出循环的条件，next作为无循环的计算。