ABAP Variables are instances of data types. Variables are created during program execution and destroyed after program execution.
Use keyword DATA to declare a variable.
DATA: firstname(10) TYPE c,
      index         TYPE i,
      student_id(5) TYPE n.
While declaring a variable we can also refer to an existing variable instead of data type. For that use LIKE instead of TYPE keyword while declaring a variable.
DATA: firstname(10) TYPE c,
      lastname(10)  LIKE firstname. " Observe LIKE keyword
Structured Variable
Similar to structured data type, structured variable can be declared using BEGIN OFand END OF keywords.
DATA: BEGIN OF student,
      id(5)     TYPE n,
      name(10)  TYPE c,
      dob       TYPE d,
      place(10) TYPE c,
      END OF student.
We can also declare a structured variable by referring to an existing structured data type.
TYPES: BEGIN OF address,
       name(10)   TYPE c,
       street(10) TYPE c,
       place(10)  TYPE c,
       pincode(6) type n,
       phone(10)  type n,
       END OF address. 

Data: house_address  type address,
      office_address like house_address.
Each individual field of the structured variable can be accessed using hyphen (-). For example, name field of the house_address structure can be accessed using housing_address-name.
Character is the default data type.
DATA: true.  " By default it will take C as data type
 
 
 
 
Serkan AKKAVAK
Computer Engineer
SAP Department Deputy Manager
Contact : serkurumsal@yandex.com