插入模式和覆盖模式
首先，我们知道在编辑文档时，有两种模式：
1、光标位置显示为 竖线，即通常使用的模式，插入模式
2、光标位置显示为 方块，即覆盖模式。
所以，两者切换方法：
1、如果目前是插入模式，点击键盘的Insert键，则切换成覆盖模式，反之同样。
2、有些笔记本电脑键盘没有Insert键咋办？
既然如此，那么快速处理编辑模式切换的问题呢？这里有两种办法：一种是外接一个有Insert的键盘，二是采用电脑的软键盘。
那么问题来了，如何开启软键盘呢？软键盘开启方法：win+R组合键，输入osk，即可显示出，键盘功能类似物理键盘。
鼠标点击Insert就可以直接切换啦！！！
变量及对象声明
1.1 变量声明
Before：
DATA text TYPE string.
text = ....
----------------------------------------
After：
DATA(text) = ....
使用工作区
DATA wa like LINE OF itab.
LOOP AT itab INTO wa.
…
ENDLOOP.
----------------------------------------
After：
LOOP AT itab INTO DATA(wa).
…
ENDLOOP.
返回参数
Before：
DATA xml TYPE xstring.
CALL TRANSFORMATION … RESULT XML xml.
----------------------------------------
After：
CALL TRANSFORMATION … RESULT XML DATA(xml).
引用声明
Before：
DATA ixml TYPE REF TO if_ixml.
DATA stream_factory TYPE REF TO if_ixml_stream_factory.
DATA document TYPE REF TO if_ixml_document.
ixml = cl_ixml=>create( ).
stream_factory = ixml->create_stream_factory( ).
document = ixml->create_document( ).
----------------------------------------
After：
DATA(ixml) = cl_ixml=>create( ).
DATA(stream_factory) = ixml->create_stream_factory( ).
DATA(document) = ixml->create_document( ).
对象实例化
Before：
DATA lo_human TYPE REF TO class_human.
CREATE OBJECT lo_human EXPORTING NAME = ‘TONY’.
----------------------------------------
After：
lo_human = NEW class_human( name = ‘TONY’ ).
内表操作
Read Table with key
Before：
READ TABLE flight_schedules INTO DATA(flight_schedule)
WITH KEY carrid = ‘AA’
connid = ‘0017’.
----------------------------------------
After：
DATA(flight_schedule) = flight_schedules[ carrid = ‘AA’ connid = ‘0017’ ].
Read Table index
Before：
READ TABLE itab INDEX idx
INTO wa.
----------------------------------------
After：
wa = itab[ idx ].
Read Table using key
Before:
READ TABLE itab INDEX idx
USING KEY key
INTO wa.
----------------------------------------
After：
wa = itab[ KEY key INDEX idx ].
Read Table index
Before:
DATA idx type sy-tabix.
READ TABLE …
TRANSPORTING NO FIELDS.
idx = sy-tabix.
----------------------------------------
After：
DATA(idx) = line_index( itab[ … ] ).
READ TABLE ASSIGNING
Before：
FIELD-SYMBOLS:
type …
READ TABLE itab
ASSIGNING .
----------------------------------------
After：
READ TABLE itab
ASSIGNING FIELD-SYMBOL(
).
获得内表行数
Before：
DATA: lv_rows TYPE i.
LV_ROWS = LINES( ITAB)
----------------------------------------
After：
DATA(lv_rows) = LINES( itab ).
填充内表的值到目标内表中
Before：
DATA: gt_citys TYPE ty_citys,
gs_ship TYPE ty_ship,
gs_city TYPE ort01.
LOOP AT gt_ships INTO gs_ship.
gs_city = gs_ship-city.
APPEND gs_city TO gt_citys.ENDLOOP.
----------------------------------------
After：
DATA(gt_citys) = VALUE ty_citys( FOR ls_ship IN gt_ships ( ls_ship-city ) ).
Open SQL
取数到内表
Before：
DATA itab TYPE TABLE OF dbtab.
SELECT * FROM dbtab
INTO TABLE itab
WHERE fld1 = lv_fld1.
----------------------------------------
After：
SELECT * FROM dbta
INTO TABLE DATA(itab)
WHERE fld1 = @lv_fld1
4.1 FILTER
FILTER type( itab [EXCEPT] [IN ftab] [USING KEY keyname]
WHERE c1 op f1 [AND c2 op f2 […]] ).
实例：
TYPES: BEGIN OF ty_filter,
cityfrom TYPE spfli–cityfrom,
cityto TYPE spfli–cityto,
f3 TYPE i,
END OF ty_filter,
ty_filter_tab TYPE HASHED TABLE OF ty_filter
WITH UNIQUE KEY cityfrom cityto.
DATA: lt_splfi TYPE STANDARD TABLE OF spfli.
SELECT * FROM spfli APPENDING TABLE lt_splfi.
DATA(lt_filter) = VALUE ty_filter_tab( f3 = 2
( cityfrom = ‘NEW YORK’ cityto = ‘SAN FRANCISCO’ )
( cityfrom = ‘FRANKFURT’ cityto = ‘NEW YORK’ ) ).DATA(lt_myrecs) = FILTER #( lt_splfi IN lt_filter
WHERE cityfrom = cityfrom
AND cityto = cityto ).
“Output filtered records
LOOP AT lt_myrecs ASSIGNING FIELD–SYMBOL(<ls_rec>).
WRITE: / <ls_rec>–carrid,8 <ls_rec>–cityfrom,30
<ls_rec>–cityto,45 <ls_rec>–deptime.
ENDLOOP.
4.2 REDUCE
… REDUCE type(
[let_exp]
INIT {x1 = rhs1}|{ = wrexpr1}|{x1| TYPE dtype1}
{x2 = rhs2}|{ = wrexpr2}|{x2| TYPE dtype2}
…
FOR for_exp1
FOR for_exp2
…
NEXT …
{x1 = rhs1}|{ = wrexpr1}
{x2 = rhs2}|{ = wrexpr2}
… ) …
实例：
DATA itab TYPE STANDARD TABLE OF i WITH EMPTY KEY.
itab = VALUE #( FOR j = 1 WHILE j <= 10 ( j ) ).DATA(sum) = REDUCE i( INIT x = 0 FOR wa IN itab NEXT x = x + wa ).
4.3 使用类转换字符串 conv
Before：
DATA text TYPE c LENGTH 255.
DATA helper TYPE string.
DATA xstr TYPE xstring.
helper = text.
xstr = cl_abap_codepage=>convert_to( source = helper ).
After：
DATA text TYPE c LENGTH 255.
DATA(xstr) = cl_abap_codepage=>convert_to( source = CONV string( text ) ).
OR
DATA(xstr) = cl_abap_codepage=>convert_to( source = CONV #( text ) ).