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Update 06_Dynamic_Programming.md

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Dan
2022-12-13 13:13:28 +01:00
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06_Dynamic_Programming.md
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@@ -30,12 +30,11 @@ Some considerations regarding "dynamic" in contrast to "static" aspects:
**are not known or not yet determined at compile time** at all. **are not known or not yet determined at compile time** at all.
- They are **only known at a program's runtime**, i. e. the - They are **only known at a program's runtime**, i. e. the
properties are defined and passed to programs at runtime. properties are defined and passed to programs at runtime.
- Consider a program that does not work with a specific kind of table - Consider a UI that allows a user to make an entry in a field. By choosing a button, some action is triggered.
but should be able to work with any kind of table, for example, a The underlying program must be able to work with whatever was inserted. Assume the program expects the name of a database table to be inserted.
user must input the table name first in a UI. The tables to be used However, the tables certainly have different properties, line types,
in the program certainly have different properties, line types,
field names, number of rows, and so on. Nevertheless, the program field names, number of rows, and so on. Nevertheless, the program
must be able to work with all of them, no matter what table is must be able to work with whatever table name was inserted and no matter what table is
processed. processed.
- You might also need to determine information about data types and - You might also need to determine information about data types and
data objects at runtime or even create them. data objects at runtime or even create them.
@@ -156,6 +155,10 @@ ASSIGN number TO FIELD-SYMBOL(<fs_inl>). "Field symbol declared inline
ASSIGN COMPONENT 2 OF STRUCTURE struc TO <fs_gen>. ASSIGN COMPONENT 2 OF STRUCTURE struc TO <fs_gen>.
ASSIGN COMPONENT 'CARRID' OF STRUCTURE struc TO <fs_gen>. ASSIGN COMPONENT 'CARRID' OF STRUCTURE struc TO <fs_gen>.
"In newer ABAP releases, you can dynamically specify components
"as follows:
ASSIGN struc-(comp1) TO <fs_gen>.
``` ```
> **💡 Note**<br> > **💡 Note**<br>
@@ -315,7 +318,7 @@ DATA(ref3) = REF string( `hallo` ).
"GET REFERENCE OF num INTO DATA(ref4). "GET REFERENCE OF num INTO DATA(ref4).
``` ```
**Creating new data objects at runtime**: You create a [anonymous **Creating new data objects at runtime**: You create an [anonymous
data data
object](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenanonymous_data_object_glosry.htm "Glossary Entry") object](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenanonymous_data_object_glosry.htm "Glossary Entry")
at runtime by placing the reference in the variable and providing the at runtime by placing the reference in the variable and providing the
@@ -398,8 +401,8 @@ operators](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?
either with the [constructor either with the [constructor
operator](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenconstructor_operator_glosry.htm "Glossary Entry") operator](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenconstructor_operator_glosry.htm "Glossary Entry")
[`CAST`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenconstructor_expression_cast.htm) [`CAST`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenconstructor_expression_cast.htm)
or the older (in older code you might see
[`?=`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abapmove_cast.htm), [`?=`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abapmove_cast.htm)),
for the assignment of data reference variables. for the assignment of data reference variables.
- See more information in - See more information in
the topic [Assignment Rules for Reference the topic [Assignment Rules for Reference
@@ -442,7 +445,7 @@ DATA ref6 TYPE REF TO data.
ref6 = NEW i( 654 ). ref6 = NEW i( 654 ).
ref5 = CAST #( ref6 ). ref5 = CAST #( ref6 ).
"Alternative syntax to the CAST operator "Alternative, yet old syntax to the CAST operator
ref5 ?= ref6. ref5 ?= ref6.
``` ```
@@ -604,7 +607,7 @@ Dynamically](https://help.sap.com/doc/abapdocu_latest_index_htm/latest/en-US/ind
## Dynamic ABAP Statements ## Dynamic ABAP Statements
Dynamic aspects come particularly into the picture when considering the Dynamic aspects particularly enter the picture when considering the
options of dynamic ABAP statements. In this context, you can make use of options of dynamic ABAP statements. In this context, you can make use of
[tokens](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abentoken_glosry.htm "Glossary Entry") [tokens](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abentoken_glosry.htm "Glossary Entry")
put within parentheses and included as operands in many ABAP statements put within parentheses and included as operands in many ABAP statements
@@ -642,7 +645,7 @@ The name of a data or object type is determined at runtime.
Examples: Examples:
``` abap ``` abap
"Anonymous data objects are created using a type determined at runtime. "Anonymous data objects are created using a type determined at runtime.
"Note that the NEW operator cannot be used here! "Note that the NEW operator cannot be used here.
CREATE DATA ref TYPE (some_type). CREATE DATA ref TYPE (some_type).
CREATE DATA ref TYPE TABLE OF (some_type). CREATE DATA ref TYPE TABLE OF (some_type).
@@ -836,7 +839,7 @@ DATA(line_type) = CAST cl_abap_structdescr(
"Defining primary table keys of internal table type to be created "Defining primary table keys of internal table type to be created
DATA(key_tab) = VALUE abap_keydescr_tab( ( name = 'CARRID' ) DATA(key_tab) = VALUE abap_keydescr_tab( ( name = 'CARRID' )
( name = 'CARRNAME' ) ). ( name = 'CARRNAME' ) ).
"Creating internal table type "Creating internal table type