Update

2025-01-13 12:49:30 +01:00
parent 6926ca4f3b
commit 401542476a
8 changed files with 863 additions and 107 deletions
--- a/01_Internal_Tables.md
+++ b/01_Internal_Tables.md
@@ -3146,6 +3146,7 @@ DATA(line_ref) = REF #( itab[ 3 ] ).
 - You can specify default values for lines that are not found to avoid an exception.
 - The first example shows catching the execption with a `TRY` control structure.
 - The `OPTIONAL` and `DEFAULT` additions can be used in the context of statements using table expressions and constructor expressions (`VALUE` and `REF` are possible). 
+- When using `OPTIONAL`, the type-specific initial value is set. After the `DEFAULT` addition, a value is expected that is convertible to the target type. You may also specify another table expression for an alternative table line to be searched.


 <br>
--- a/02_Structures.md
+++ b/02_Structures.md
@@ -10,6 +10,8 @@
    - [Creating Structures](#creating-structures)
    - [Creating Structures Using Existing Structured Types](#creating-structures-using-existing-structured-types)
    - [Creating Structures by Inline Declaration](#creating-structures-by-inline-declaration)
+    - [Creating Constant and Immutable Structures](#creating-constant-and-immutable-structures)
+    - [Creating Enumerated Structures](#creating-enumerated-structures)
    - [Creating Anonymous Structures](#creating-anonymous-structures)
  - [Variants of Structures](#variants-of-structures)
  - [Accessing (Components of) Structures](#accessing-components-of-structures)
@@ -251,6 +253,67 @@ LOOP AT itab INTO DATA(wa_2).
 ENDLOOP.
 ```

+<p align="right"><a href="#top">⬆️ back to top</a></p>
+
+###  Creating Constant and Immutable Structures
+
+- Constant structures can be created with the `... BEGIN OF ... END OF ...` additions. Their values cannot be changed.
+- As shown above, the [`FINAL`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenfinal_inline.htm) declaration operator is used to create [immutable variables](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenimmutable_variable_glosry.htm).
+
+```abap
+CONSTANTS: BEGIN OF const_struct,
+             num TYPE i VALUE 123,
+             str TYPE string VALUE `ABAP`,
+             n3  TYPE n LENGTH 3 VALUE '000',
+             c5  TYPE c LENGTH 5 VALUE 'abcde',
+           END OF const_struct.
+
+DATA(num) = const_struct-num.
+"const_struct-num = 456.
+
+TYPES struct_type LIKE const_struct.
+FINAL(final_struct) = VALUE struct_type( num = 987 str = `hello` n3 = '123' c5 = 'xyz' ).
+
+DATA(num_from_final) = final_struct-num.
+"final_struct-num = 1.
+
+SELECT * FROM zdemo_abap_carr INTO TABLE @DATA(itab).
+
+"The work area is specified as immutable variable. The variable's content cannot be changed
+"in the loop, however, the variable is exchanged with the next loop pass.
+LOOP AT itab INTO FINAL(wa).
+  DATA(carrid) = wa-carrid.
+  "wa-carrid = 'XY'.
+ENDLOOP.
+```
+
+<p align="right"><a href="#top">⬆️ back to top</a></p>
+
+### Creating Enumerated Structures
+
+Find more information on [enumerated types](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenenum_type_glosry.htm) in the [Data Types and Data Objects](16_Data_Types_and_Objects.md#abap-enumerated-types-and-objects) cheat sheet.
+
+```abap
+"When creating enumerated types, an enumerated structure can optionally be declared in 
+"the context of the type declaration.
+"A component of an enumerated structure: An enumerated constant that exists as a component
+"of a constant structure, not as a single data object.
+TYPES basetype TYPE i.
+TYPES: BEGIN OF ENUM t_enum_struc STRUCTURE en_struc BASE TYPE basetype,
+         a VALUE IS INITIAL,
+         b VALUE 1,
+         c VALUE 2,
+         d VALUE 3,
+       END OF ENUM t_enum_struc STRUCTURE en_struc.
+
+DATA(enum_comp) = en_struc-b.
+
+DATA(conv_enum_comp) = CONV basetype( en_struc-b ).
+ASSERT conv_enum_comp = 1.
+```
+
+<p align="right"><a href="#top">⬆️ back to top</a></p>
+
 ### Creating Anonymous Structures

 Using the instance operator [`NEW`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenconstructor_expression_new.htm) and [`CREATE DATA`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abapcreate_data.htm) statements, you can create [anonymous data objects](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenanonymous_data_object_glosry.htm "Glossary Entry"), such as anonymous structures. 
--- a/04_ABAP_Object_Orientation.md
+++ b/04_ABAP_Object_Orientation.md
--- a/06_Dynamic_Programming.md
+++ b/06_Dynamic_Programming.md
@@ -430,6 +430,9 @@ ASSIGN s-xl1 TO <simple>.
 ASSIGN s-oref TO <object>.
 ```

+> **💡 Note**<br>
+> After `TYPE REF TO`, the only generic types you can specify are `data` for fully generic data reference variables and `object` for fully generic object reference variables.
+
 <p align="right"><a href="#top">⬆️ back to top</a></p>

 ### Data References
--- a/13_Program_Flow_Logic.md
+++ b/13_Program_Flow_Logic.md
@@ -9,6 +9,7 @@
    - [`IF` Statements](#if-statements)
      - [Excursion: `COND` Operator](#excursion-cond-operator)
    - [`CASE`: Case Distinctions](#case-case-distinctions)
+      - [Control Structures Using CASE TYPE OF](#control-structures-using-case-type-of)
      - [Excursion: `SWITCH` Operator](#excursion-switch-operator)
    - [Loops](#loops)
      - [`DO`: Unconditional Loops](#do-unconditional-loops)
@@ -355,6 +356,10 @@ CASE random_num.
 ENDCASE.
 ```

+<p align="right"><a href="#top">⬆️ back to top</a></p>
+
+#### Control Structures Using CASE TYPE OF 
+
 Special control structure introduced by [`CASE TYPE OF`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abapcase_type.htm): Checks the type of object reference variables. An object reference variable with the static type of a class or an interface must be specified after `CASE TYPE OF`.

 ```abap
@@ -547,7 +552,7 @@ Further keywords for defining loops are as follows. They are not dealt with here

 - [`LOOP ... ENDLOOP`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abaploop_at_itab.htm) statements are meant for loops across internal tables. See also the cheat sheet on internal tables.
  - In contrast to the loops above, the system field `sy-index` is not set. Instead, the system field `sy-tabix` is set and which contains the table index of the current table line in the loop pass.
-  - You can also realize loops using iteration expressions with `VALUE` and `REDUCE`. For more information, refer to the [Constructor Expressions](05_Constructor_Expressions.md) cheat sheet.
+- `FOR` loops: You can also realize loops using iteration expressions with `VALUE` and `REDUCE`. For more information, refer to the [Constructor Expressions](05_Constructor_Expressions.md) cheat sheet.
 - [`SELECT ... ENDSELECT`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abapselect.htm) statements loop across the result set of a database access. See also the cheat sheet on ABAP SQL.

 <p align="right"><a href="#top">⬆️ back to top</a></p>
--- a/16_Data_Types_and_Objects.md
+++ b/16_Data_Types_and_Objects.md
@@ -166,6 +166,8 @@ TYPES te_utc TYPE utclong.
 "You might also stumble on a length specification in parentheses following the data type name.
 "It is recommended that you use addition LENGTH instead of the parentheses.
 TYPES te_cfour(4) TYPE c.
+TYPES te_nfive(5) TYPE n.
+TYPES te_xtwo(2) TYPE x.

 "**** Data type declarations based on existing types or data objects ****

@@ -509,7 +511,9 @@ DATA: do_i       TYPE i,
      do_str     TYPE string,
      "Specifying the length in parantheses instead of using the
      "LENGTH addition is not recommended
-      do_ctwo(2) TYPE c.
+      do_ctwo(2) TYPE c,
+      do_nthree(3) TYPE n,
+      do_xfour(4) TYPE x.

 "Referring to locally declared data types
 TYPES te_string TYPE string.
@@ -1461,7 +1465,7 @@ ENDCLASS.

 <p align="right"><a href="#top">⬆️ back to top</a></p>

-### ABAP Enumerated Types and Objects
+## ABAP Enumerated Types and Objects
 - ABAP supports the concept of enumerations. 
 - Enumerations are a mixture of types and constants.
 - An [enumerated type](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenenum_type_glosry.htm) specifies a value set in addition to the actual type properties. 
@@ -1789,6 +1793,9 @@ do_h_c3 = 'abc'.
 "here like this) is not an admissable value for the target type. 
 do_h_c3 = 'defghi'. 

+"'j' assigned, but length and memory do not change
+do_h_c3 = 'j'. 
+
 "Memory consumption changes for dynamic data objects
 do_i_str = `abc`.
 do_i_str = `d`.
@@ -2065,6 +2072,37 @@ DATA itab5 TYPE zcl_demo_abap_amdp=>carr_tab.
 <tr>
 <td> 

+`TYPE BEGIN OF`
+
+ </td>
+
+ <td> 
+
+
+``` abap
+"------------ TYPE BEGIN OF ----------------
+
+"Structured types and data objects created with TYPE BEGIN OF ... END OF ...
+
+TYPES: BEGIN OF some_struct_type,
+          comp1 TYPE i,
+          comp2 TYPE string,
+          comp3 TYPE c LENGTH 3,
+       END OF some_struct_type.
+
+DATA: BEGIN OF some_struct,
+        compa TYPE n LENGTH 5,
+        compb TYPE xstring,
+        compc TYPE p LENGTH 8 DECIMALS 2,
+      END OF some_struct.
+``` 
+
+ </td>
+</tr>
+
+<tr>
+<td> 
+
 `TYPE TABLE OF`

 </td>
@@ -2488,7 +2526,7 @@ SELECT SINGLE

 ### Non-Admissible Values of Literals

-Note recent syntax warnings when using literals that represent invalid values for target types. The following example demonstrates the assignment of literals using admissible and non-admissible values. You can copy and paste the code into a demo class in your SAP BTP ABAP Environment to explore the syntax warnings.
+Syntax warnings are displayed when using literals that represent invalid values for target types. The following example demonstrates the assignment of literals using admissible and non-admissible values. You can copy and paste the code into a demo class in your SAP BTP ABAP Environment to explore the syntax warnings.


 ```abap
--- a/22_Released_ABAP_Classes.md
+++ b/22_Released_ABAP_Classes.md
@@ -2344,7 +2344,7 @@ DATA table_json_to_abap TYPE string_table.

 <ul>
 <li>Provides access to abstractions for ABAP Dictionary objects such as database tables, data elements, types and more.</li>
-<li>For more detailed examples, refer to the <a href="https://help.sap.com/docs/btp/sap-business-technology-platform/overview-of-xco-modules">SAP Help Portal</a>. See also the executable example of the ABAP for Cloud Development cheat sheet.</li>
+<li>For more detailed examples, refer to the <a href="https://help.sap.com/docs/btp/sap-business-technology-platform/overview-of-xco-modules">SAP Help Portal</a>. See also the executable example of the <a href="19_ABAP_for_Cloud_Development.md">ABAP for Cloud Development</a> cheat sheet.</li>
 <li>The code snippet contains a small selection and only hints at the many ways to retrieve different pieces of information that the classes provide.</li>
 <li>The snippet does not only include the <code>XCO_CP_ABAP_REPOSITORY</code> class but also others such as <code>XCO_CP_ABAP</code>, <code>XCO_CP_ABAP_SQL</code>, and <code>XCO_CP_CDS</code>. More XCO classes are available in that context.</li>
 </ul>
@@ -2704,7 +2704,9 @@ DATA(sub_acc_id) = ten->get_subaccount_id( )->as_string( ).
 <tr>
 <td> <code>CX_*</code> </td>
 <td>
+
 Exception classes are special classes, usually starting with the name <code>CX_*</code>, that serve as the basis for <a href="https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abencatchable_exception_glosry.htm">catchable exceptions</a>. When an exception is raised, an object of such an exception class is created. There are several predefined exception classes. Find more information in the [Exceptions and Runtime Errors](27_Exceptions.md) cheat sheet. 
+
 <br><br>

 ``` abap
@@ -3301,6 +3303,8 @@ To check out examples in demo classes, expand the collapsible sections below.
  <summary>🟢 1. Read example: Retrieving ABAP cheat sheet markdown content using a GitHub API and sending a ZIP file with the content via email</summary>
  <!-- -->

+<br>
+
 > **⚠️ Note/Disclaimer**<br>
 > - The following self-contained and oversimplified example is not a representative best practice example, nor does it cover a meaningful use case. It only explores method calls and is intended to give a rough idea of the functionality.</li>
 > - The example uses the <code>create_by_url</code> method, which is only suitable for public services or testing purposes. No authentication is required for the APIs used.
@@ -3465,6 +3469,8 @@ ENDCLASS.
  <summary>🟢 2. Post example: Demonstrating a post request by converting Markdown to HTML using the GitHub API</summary>
  <!-- -->

+<br>
+
 > **⚠️ Note/Disclaimer**<br>
 > - As stated for the previous example, also note for this example: Before using the GitHub APIs, make sure that you have consulted the following documentation: <a href="https://docs.github.com/en">GitHub Docs</a>, <a href="https://docs.github.com/en/enterprise-cloud@latest/rest/markdown/markdown?apiVersion=2022-11-28#render-a-markdown-document">Render a Markdown document</a>, <a href="https://docs.github.com/en/rest/using-the-rest-api/rate-limits-for-the-rest-api?apiVersion=2022-11-28">Rate limits for the REST API</a>
 > - To run the example class, copy and paste the code into a class named `zcl_demo_abap`. Run the class using F9. It is set up to display HTML content in the console. Using the GitHub API, sample Markdown content is sent and converted to HTML.
--- a/27_Exceptions.md
+++ b/27_Exceptions.md
@@ -14,6 +14,7 @@
      - [RETRY Statements](#retry-statements)
      - [RESUME Statements and RESUMABLE Additions](#resume-statements-and-resumable-additions)
  - [Using Messages as Exception Texts](#using-messages-as-exception-texts)
+    - [System Interfaces for Messages](#system-interfaces-for-messages)
    - [Excursion: MESSAGE Statements](#excursion-message-statements)
  - [Syntax Variants of RAISE EXCEPTION/THROW](#syntax-variants-of-raise-exceptionthrow)
  - [Runtime Errors](#runtime-errors)
@@ -851,6 +852,13 @@ ENDLOOP.
 - If an exception is raised and ...
  - not handled, the exception text is displayed in the [short dump](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenshort_dump_glosry.htm) of the runtime error.
  - handled, the text can be retrieved using the `get_text` method as shown above.
+- As outlined in the next section, exception classes must implement one of the system interfaces for messages to use exception texts.
+ 
+
+<p align="right"><a href="#top">⬆️ back to top</a></p>
+
+### System Interfaces for Messages
+
 - Exception classes must implement one of the system interfaces for messages to use exception texts:
  - `IF_T100_MESSAGE`:
    - Contains the `T100KEY` structured attribute (type `SCX_T100KEY`), specifying a message in the `T100` database table. Components are: `msgid` for the message class, `msgno` for the message number, and `attr1`/`attr2`/`attr3`/`attr4` for potential placeholders in message texts.