ABAP Data Types

ABAP (Advanced Business Application Programming) provides a variety of data types that are used to define variables and constants in programs. Understanding data types is crucial for writing efficient and effective ABAP code.

Elementary Data Types

Numeric Data Types

I (Integer): Used for whole numbers.
```
DATA: lv_number TYPE I.
```
F (Floating-point number): Used for floating-point numbers.
```
DATA: lv_float TYPE F.
```
P (Packed number/Decimal): Used for decimal numbers with a specified number of decimal places.
```
DATA: lv_amount TYPE P DECIMALS 2.
```

Character Data Types

C (Character): Used for fixed-length character strings.
```
DATA: lv_char TYPE C LENGTH 10.
```
N (Numeric text): Used for numeric text strings (digits only).
```
DATA: lv_numtext TYPE N LENGTH 5.
```
D (Date): Used for date values in the format YYYYMMDD.
```
DATA: lv_date TYPE D.
```
T (Time): Used for time values in the format HHMMSS.
```
DATA: lv_time TYPE T.
```
STRING: Used for variable-length character strings.
```
DATA: lv_string TYPE STRING.
```

Byte Data Types

X (Hexadecimal): Used for hexadecimal values.
```
DATA: lv_hex TYPE X LENGTH 4.
```
XSTRING: Used for variable-length hexadecimal strings.
```
DATA: lv_xstring TYPE XSTRING.
```

Complex Data Types

Structures

A structure is a grouping of fields, each of which can have a different data type.

TYPES: BEGIN OF ty_structure,
           field1 TYPE I,
           field2 TYPE C LENGTH 10,
       END OF ty_structure.

DATA: ls_structure TYPE ty_structure.

Internal Tables

Internal tables are used to store collections of data in rows, similar to arrays.

TYPES: BEGIN OF ty_table,
           field1 TYPE I,
           field2 TYPE C LENGTH 10,
       END OF ty_table.

DATA: lt_table TYPE TABLE OF ty_table.

References and Object Types

REF TO: Used for object references.

DATA: lo_object TYPE REF TO cl_example_class.

Constants

Constants in ABAP are variables whose value cannot be changed once defined.
```
CONSTANTS: lc_pi TYPE P DECIMALS 2 VALUE '3.14'.
```

Example Usage

REPORT z_data_types_example.

DATA: lv_int    TYPE I VALUE 100,
      lv_char   TYPE C LENGTH 5 VALUE 'ABAP',
      lv_date   TYPE D VALUE '20230101',
      lv_amount TYPE P DECIMALS 2 VALUE '1234.56'.

WRITE: / 'Integer:', lv_int,
       / 'Character:', lv_char,
       / 'Date:', lv_date,
       / 'Amount:', lv_amount.

Comprehensive ABAP Types with Hungarian Notation

Integer

Type: Integer
Hungarian Notation: i_
Example: i_counter

Character/String

Type: Character/String
Hungarian Notation: c_
Example: c_name

Packed Number (Decimal)

Type: Packed Number (Decimal)
Hungarian Notation: p_
Example: p_amount

Floating-point Number

Type: Floating-point Number
Hungarian Notation: f_
Example: f_value

Date

Type: Date
Hungarian Notation: d_
Example: d_start_date

Time

Type: Time
Hungarian Notation: t_
Example: t_end_time

Boolean/Logical

Type: Boolean/Logical
Hungarian Notation: l_
Example: l_flag

Reference

Type: Reference
Hungarian Notation: r_ or lo_
Example: r_pointer, lo_employee

Local Variable

Type: Local Variable
Hungarian Notation: lv_
Example: lv_temp

Global Variable

Type: Global Variable
Hungarian Notation: gv_
Example: gv_total

Global Internal Table

Type: Global Internal Table
Hungarian Notation: gt_
Example: gt_data

Local Internal Table

Type: Local Internal Table
Hungarian Notation: lt_
Example: lt_employees

Global Structure

Type: Global Structure
Hungarian Notation: gs_
Example: gs_employee

Local Structure

Type: Local Structure
Hungarian Notation: ls_
Example: ls_record

Type Table

Type: Type Table
Hungarian Notation: tt_
Example: tt_employee_table

Type Definition

Type: Type Definition
Hungarian Notation: ty_
Example: ty_employee

Class Name

Type: Class Name
Hungarian Notation: cl_
Example: cl_employee

Interface Name

Type: Interface Name
Hungarian Notation: if_
Example: if_employee_handler

Constant

Type: Constant
Hungarian Notation: co_
Example: co_max_value

Member Object

Type: Member Object
Hungarian Notation: mo_
Example: mo_employee

Member Table

Type: Member Table
Hungarian Notation: mt_
Example: mt_employee_list

Member Structure

Type: Member Structure
Hungarian Notation: ms_
Example: ms_employee_data

System Variables

Type: System Variables (not a prefix, but commonly used)
Hungarian Notation: sy_
Example: sy-datum (current date)

Type	Hungarian Notation	Example	Description
Integer	i_	i_counter	An integer is a whole number without a decimal point. Used for counters, iterations, etc.
Character/String	c_	c_name	A character or string is a sequence of characters. Used for names, descriptions, etc.
Packed Number (Decimal)	p_	p_amount	A packed number is a decimal number stored in a compact format. Used for monetary values, quantities, etc.
Floating-point Number	f_	f_value	A floating-point number represents a real number with fractional parts. Used for values requiring precision, like scientific measurements.
Date	d_	d_start_date	A date is a point in time typically represented as day, month, and year. Used for date fields.
Time	t_	t_end_time	A time represents a specific time of day, usually as hours, minutes, and seconds. Used for time fields.
Boolean/Logical	l_	l_flag	A boolean or logical type represents truth values: true or false. Used for flags, switches, etc.
Reference	r_ or lo_	r_pointer, lo_employee	A reference or object pointer to another object or data type. Used for referencing objects in ABAP.
Local Variable	lv_	lv_temp	A local variable is a variable declared within a function or method, accessible only within that scope.
Global Variable	gv_	gv_total	A global variable is accessible throughout the entire program or module, regardless of scope.
Global Internal Table	gt_	gt_data	A global internal table is a table that can be accessed globally across the program.
Local Internal Table	lt_	lt_employees	A local internal table is a temporary table used within a local scope, such as within a method or function.
Global Structure	gs_	gs_employee	A global structure is a complex data type that can hold multiple fields of different data types, accessible globally.
Local Structure	ls_	ls_record	A local structure is a complex data type with multiple fields of different data types, accessible locally.
Type Table	tt_	tt_employee_table	A type table is a predefined type that defines the structure of internal tables.
Type Definition	ty_	ty_employee	A type definition creates a custom type used for defining variables or structures.
Class Name	cl_	cl_employee	A class name is the name of a class, which is a blueprint for creating objects in ABAP.
Interface Name	if_	if_employee_handler	An interface name defines a set of methods that a class must implement.
Constant	co_	co_max_value	A constant is a value that cannot be changed during the program execution.
Member Object	mo_	mo_employee	A member object is an instance of a class, representing a specific realization of the class.
Member Table	mt_	mt_employee_list	A member table is an internal table that is a member of a class, used to store multiple entries.
Member Structure	ms_	ms_employee_data	A member structure is a structure that is a member of a class, used to group related data fields.
System Variables	sy_	sy-datum	System variables are predefined variables provided by the SAP system, often used for system-related information.

Basic syntax

Variables