Correct ABAP md highlights
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danrega
@@ -29,9 +29,11 @@
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- See the following `SELECT` statement. As also shown further down, the `FROM` clause does not include a statically defined table to be selected from. Instead, there is a pair of parentheses including a data object. Assume the data object holds the name of the database table. At runtime, the data retrieval happens from the database table that was inserted in the input field.
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```abap
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DATA(dbtab) = `ZDEMO_ABAP_FLI`.
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SELECT *
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FROM (dbtab)
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INTO TABLE @DATA(some_itab).
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FROM (dbtab)
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INTO TABLE @DATA(some_itab).
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```
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- Further aspects for dynamic programming in ABAP enter the picture if you want to determine information about data types and data objects at runtime ([RTTI](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenrun_time_type_identific_glosry.htm)) or even create them ([RTTC](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenrun_time_type_creation_glosry.htm)).
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@@ -105,9 +107,9 @@ Once the memory area is assigned, you can work with the content.
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``` abap
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"Some data object declarations to be used
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DATA: number TYPE i,
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struc TYPE zdemo_abap_fli, "Demo database table
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tab TYPE string_table.
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DATA: num TYPE i,
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struc TYPE zdemo_abap_fli, "Demo database table
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tab TYPE string_table.
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"Declaring field symbols with complete types
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FIELD-SYMBOLS: <fs_i> TYPE i,
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@@ -119,14 +121,14 @@ FIELD-SYMBOLS <fs_gen> TYPE data.
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"Assigning data objects to field symbols
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"Note: In this case, the field symbols have an appropriate type.
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ASSIGN number TO <fs_i>.
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ASSIGN struc TO <fs_struc>.
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ASSIGN tab TO <fs_tab>.
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ASSIGN number TO <fs_gen>. "Could be any of the data objects
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ASSIGN num TO <fs_i>.
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ASSIGN struc TO <fs_struc>.
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ASSIGN tab TO <fs_tab>.
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ASSIGN num TO <fs_gen>. "Could be any of the data objects
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"Inline declaration is possible, too. The type
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"is automatically derived.
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ASSIGN number TO FIELD-SYMBOL(<fs_inl>).
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ASSIGN num TO FIELD-SYMBOL(<fs_inl>).
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"You can also assign a particular component of a structure.
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"Second component of the structure
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@@ -168,17 +170,18 @@ ASSIGN chars TO <fs2> CASTING TYPE c_len_3.
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``` abap
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"For example, in assignments
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DATA number TYPE i VALUE 1.
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DATA num TYPE i VALUE 1.
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FIELD-SYMBOLS <fs_i> TYPE i.
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ASSIGN number TO <fs_i>.
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ASSIGN num TO <fs_i>.
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<fs_i> = 2.
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"The data object 'number' has now the value 2.
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"The data object 'num' has now the value 2.
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"Loops
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"Here, field symbols are handy since you can avoid an
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"actual copying of the table line to boost performance.
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SELECT * FROM zdemo_abap_fli
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SELECT *
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FROM zdemo_abap_fli
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INTO TABLE @DATA(itab).
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FIELD-SYMBOLS <fs1> LIKE LINE OF itab.
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@@ -261,8 +264,7 @@ DATA(ref2) = REF #( num ).
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DATA(ref3) = REF string( `hallo` ).
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"The older syntax GET REFERENCE having the same effect
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"should not be used anymore.
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"The older syntax GET REFERENCE having the same effect should not be used anymore.
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"GET REFERENCE OF num INTO ref1.
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"GET REFERENCE OF num INTO DATA(ref4).
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```
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@@ -272,8 +274,7 @@ data object](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.ht
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at runtime by assigning the reference to the data object of a data reference variable. You can use the [instance
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operator](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abeninstance_operator_glosry.htm "Glossary Entry")
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[`NEW`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenconstructor_expression_new.htm).
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The older syntax [`CREATE DATA`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abapcreate_data.htm)
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has the same effect as using the newer instance operator.
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It replaces the older syntax [`CREATE DATA`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abapcreate_data.htm). However, as shown further, `CREATE DATA` is required for specifying a dynamically determined type.
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``` abap
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"Declaring data reference variables
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@@ -300,17 +301,15 @@ TYPES i_table TYPE STANDARD TABLE OF i WITH EMPTY KEY.
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DATA(ref3) = NEW i_table( ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ).
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"CREATE DATA statements (older syntax)
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"Unlike above, the older syntax is not commented out. CREATE DATA is used for dynamic
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"type specification as shown further down.
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DATA ref4 TYPE REF TO string.
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DATA ref5 TYPE REF TO data.
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"DATA ref4 TYPE REF TO string.
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"DATA ref5 TYPE REF TO data.
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CREATE DATA ref4.
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"CREATE DATA ref4.
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"Note: TYPE ... needed because of generic type data
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CREATE DATA ref5 TYPE p LENGTH 6 DECIMALS 2.
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"CREATE DATA ref5 TYPE p LENGTH 6 DECIMALS 2.
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CREATE DATA ref5 LIKE ref4.
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"CREATE DATA ref5 LIKE ref4.
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```
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**Assigning existing data references** to other data references. As mentioned above regarding the assignment, note that static types of both data
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@@ -327,8 +326,8 @@ Excursion: Static vs. dynamic type, upcasts and downcasts
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- Upcast: If the static type of the target variables is **less specific or the same** as the static type of the source variable, an assignment is possible. This includes, for example, assignments with the [assignment operator](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenassignment_operator_glosry.htm) `=`.
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- Downcast: If the static type of the target variable is **more specific** than the static type of the source variable, a check must be made at runtime before the assignment is done. If you indeed want to trigger such a downcast, you must do it explicitly in your code. You can do this, for example, using the
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[constructor operator](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenconstructor_operator_glosry.htm "Glossary Entry")
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[`CAST`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenconstructor_expression_cast.htm). In older code, you might see
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the operator [`?=`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abapmove_cast.htm).
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[`CAST`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abenconstructor_expression_cast.htm). In older code, you may see the use of
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[`?=`](https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/index.htm?file=abapmove_cast.htm) operator.
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- In contrast to a downcast, an upcast does not have to be done explicitly. However, you can - but need not - use the mentioned operators for upcasts, too.
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@@ -364,7 +363,7 @@ DATA ref6 TYPE REF TO data.
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ref6 = NEW i( 654 ).
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ref5 = CAST #( ref6 ).
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"Casting operator: Older syntax
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"Casting operator in older syntax
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"ref5 ?= ref6.
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```
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@@ -430,11 +429,11 @@ Some example contexts of using data references are as follows:
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**Overwriting data reference variables**:
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``` abap
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ref = NEW i( 1 ).
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dref = NEW i( 1 ).
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"ref is overwritten here because a new object is created
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"with a data reference variable already pointing to a data object
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ref = NEW i( 2 ).
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dref = NEW i( 2 ).
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```
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**Retaining data references**:
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@@ -444,20 +443,20 @@ ref = NEW i( 2 ).
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"with the same reference variable. Storing them in an internal table
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"using the TYPE TABLE OF REF TO prevents the overwriting.
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DATA: ref TYPE REF TO data,
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itab TYPE TABLE OF REF TO data,
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number TYPE i VALUE 0.
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DATA: dref TYPE REF TO data,
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itab TYPE TABLE OF REF TO data,
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num TYPE i VALUE 0.
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DO 3 TIMES.
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"Adding up 1 to demonstrate a changed data object.
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number += 1.
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num += 1.
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"Creating data reference and assigning value.
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"In the course of the loop, the variable gets overwritten.
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ref = NEW i( number ).
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dref = NEW i( num ).
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"Adding the reference to itab
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itab = VALUE #( BASE itab ( ref ) ).
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itab = VALUE #( BASE itab ( dref ) ).
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ENDDO.
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```
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@@ -469,7 +468,8 @@ ENDDO.
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"instead of actually copying the content to boost performance.
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"Filling an internal table.
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SELECT * FROM zdemo_abap_fli
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SELECT *
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FROM zdemo_abap_fli
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INTO TABLE @DATA(fli_tab).
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LOOP AT fli_tab REFERENCE INTO DATA(ref).
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@@ -563,8 +563,8 @@ Note that dynamically specifying syntax elements has downsides, too. Consider so
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"Anonymous data objects are created using a type determined at runtime.
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"Note that the NEW operator cannot be used here.
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CREATE DATA ref TYPE (some_type).
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CREATE DATA ref TYPE TABLE OF (some_type).
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CREATE DATA dref TYPE (some_type).
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CREATE DATA dref TYPE TABLE OF (some_type).
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"Assigning a data object to a field symbol casting a dynamically specified type
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