ABAP中的系统变量SY-INDEX与SY-TABIX区别

系统变量SY-INDEX与SY-TABIX是用来记录循环的次数或者索引的。
不同的是SY-INDEX在DO....ENDDO中是有效的，而SY-TABIX在LOOP....ENDLOOP中及READ内表时获取相应的索引。

下面的小实例，一看就明白了

1. DATA:BEGIN OF student OCCURS 0,
   
2.         name(10) TYPE c,
   
3.         age TYPE i,
   
4.      END OF student.
   
5. 
   
6. DATA dent LIKE LINE OF student.
   
7. 
   
8. student-name = 'JACK'.
   
9. student-age = 20.
   
10. APPEND student.
    
11. 
    
12. student-name = 'JIM'.
    
13. student-age = 25.
    
14. APPEND student.
    
15. 
    
16. student-name = 'TOMMY'.
    
17. student-age = 28.
    
18. APPEND student.
    
19. 
    
20. student-name = 'BUSHI'.
    
21. student-age = 20.
    
22. APPEND student.
    
23. 
    
24. student-name = 'LILY'.
    
25. student-age = 26.
    
26. APPEND student.
    
27. 
    
28. student-name = 'ALEX'.
    
29. student-age = 28.
    
30. APPEND student.
    
31. 
    
32. WRITE: '1.LOOP循环'.
    
33. WRITE: / '-----------------------------------------------'.
    
34. LOOP AT student.
    
35. 
    
36.   WRITE: / 'SY-INDEX=',sy-index LEFT-JUSTIFIED, "LEFT-JUSTIFIED  输出向左对齐
    
37.            'SY-TABIX=',sy-tabix LEFT-JUSTIFIED,
    
38.            'NAME=',student-name LEFT-JUSTIFIED,
    
39.            'AGE=',student-age LEFT-JUSTIFIED.
    
40. ENDLOOP.
    
41. 
    
42. WRITE: / '-----------------------------------------------'.
    
43. WRITE: / '2.READ INTERNAL TABLE'.
    
44. WRITE: / '-----------------------------------------------'.
    
45. READ TABLE student INTO dent WITH KEY name = 'ALEX'. "按具体字段值读取内表
    
46. WRITE: /   'SY-INDEX=',sy-index LEFT-JUSTIFIED,
    
47.            'SY-TABIX=',sy-tabix LEFT-JUSTIFIED, "读取内表时，返回相应数据在内表中的索引
    
48.            'NAME=',dent-name LEFT-JUSTIFIED,
    
49.            'AGE=',dent-age LEFT-JUSTIFIED.
    
50. 
    
51. 
    
52. READ TABLE student INTO dent WITH KEY name = 'BUSHI'. "按具体字段值读取内表
    
53. WRITE: /'SY-INDEX=',sy-index LEFT-JUSTIFIED,
    
54.         'SY-TABIX=',sy-tabix LEFT-JUSTIFIED,
    
55.         'NAME=',dent-name LEFT-JUSTIFIED,
    
56.         'AGE=',dent-age LEFT-JUSTIFIED.
    
57. CLEAR sy-tabix.
    
58. 
    
59. WRITE: / '-----------------------------------------------'.
    
60. WRITE: / '3.DO...ENDDO'.
    
61. WRITE: / '-----------------------------------------------'.
    
62. 
    
63. DO 5 TIMES.
    
64.   WRITE:/ 'SY-INDEX=',sy-index LEFT-JUSTIFIED,
    
65.           'SY-TABIX=',sy-tabix LEFT-JUSTIFIED.
    
66. ENDDO.
    
67. 
    
68. WRITE: / '-----------------------------------------------'.

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程序执行结果：