[ABAP] How do I create and use enums and constants in ABAP?

In ABAP, enums and constants can be created and used as follows:

1. Enumerations (Enums):

   • Declare an enumeration type using the ENUM statement followed by the name of the enum and the possible values enclosed in parentheses.

   • Example: TYPES: enum_name TYPE ENUM ('Value1', 'Value2', 'Value3').

   • Use the enum type to declare variables and table fields.

   • Example: DATA: enum_var TYPE enum_name.

   • Assign a value to an enum variable using the corresponding enum constant.

   • Example: enum_var = enum_name->Value1.

   • Enums can be used in CASE statements and comparisons.

   • Example:

     1CASE enum_var.
     2  WHEN enum_name->Value1.
     3    " do something
     4  WHEN enum_name->Value2.
     5    " do something else
     6ENDCASE.
     

2. Constants:

   • Declare a constant using the CONSTANTS statement followed by the name of the constant, the data type, and the value.

   • Example: CONSTANTS c_name TYPE c_type VALUE 'Constant Value'.

   • Use the constant by referring to its name in your code.

   • Example: WRITE: / c_name.

   • Constants can be used in calculations and comparisons.

   • Example:

     1DATA(lv_result) = c_value1 + c_value2.
     2IF lv_result = c_value3.
     3  " do something
     4ENDIF.
     

Note: Enums and constants should be declared at the beginning of the ABAP program or in a global include to ensure their availability throughout the program.