data type

[Former Member]

what is the difference between keywords TYPE and LIKE ??? when to use TYPE and when to use LIKE

[Former Member]

Hi,

type we can use to refer system defined or user defined data types and data dictionary objects..

like we will use in case of refering data dictionary objects only.

Here the links in detail...

Regards,

Harish

[Former Member]

hi,

TYPE: refers to Data type.

LIKE : refers to data object.

The Additions TYPE and LIKE

The additions TYPE type and LIKE dobj are used in various ABAP statements. The additions can have various meanings, depending on the syntax and context.

· Definition of local types in a program

· Declaration of data objects

· Dynamic creation of data objects

· Specification of the type of formal parameters in subroutines

· Specification of the type of formal parameters in methods

· Specification of the type of field symbols

Constructing New Data Types

The TYPE addition allows you to construct new data types in the TYPES, DATA; CONSTANTS; and STATICSstatements. In the TYPES statement, these are local data types in the program. In the other statements, they are attributes of new data objects, meaning that the newly defined data types are not free-standing. Rather, they are linked to database objects.This means that you can refer to them using the LIKEaddition, but not using TYPE.

To construct new data types, the addition TYPE can be used with the following type constructors:

· Construction of reference types

REF TO type|dobj

· Construction of structured data types

BEGIN OF struc_type.

...

END OF struc_type.

· Construction of table types

tabkind OF linetype

These data types only exist during the runtime of the ABAP program.

Referring to Known Data Types or Data Objects

Using the additions TYPE or LIKE in the TYPESstatement, local data types in a program can be referred to known data types or data objects. This is mainly the case with user-defined elementary data types. If you declare variables using the additions TYPE type or LIKE dobj with statement DATA, the data type of var is already fully defined before the declaration is made.

The known types or data that are referred to must be visible at the point where the data type or variable is declared.

A known data type can be any of the following:

· A predefined ABAP type to which you refer using the TYPE addition

· An existing local data type in the program to which you refer using the TYPE addition

· The data type of a local data object in the program to which you refer using the LIKE addition

· A data type in the ABAP Dictionary to which you refer using the TYPE addition. To ensure compatibility with earlier releases, it is still possible to use the LIKE addition to refer to database tables and flat structures in the ABAP Dictionary. However, you should use the TYPE addition in new programs.

The LIKE addition takes its technical attributes from a visible data object. As a rule, you can use LIKE to refer to any object that has been declared using DATA or a similar statement, and is visible in the current context. The data object only has to have been declared. It is irrelevant whether the data object already exists in memory when you make the LIKE reference.

· In principle, the local data objects in the same program are visible. As with local data types, there is a difference between local data objects in procedures and global data objects. Data objects defined in a procedure obscure other objects with the same name that are declared in the global declarations of the program.

· You can also refer to the data objects of other visible ABAP programs. These might be, for example, the visible attributes of global classes in class pools. If a global class cl_lobal has a public instance attribute or static attribute attr, you can refer to it as follows in any ABAP program:

DATA dref TYPE REF TO cl_global.

DATA: f1 LIKE cl_global=>attr,

f2 LIKE dref->attr.

thanks,

raji

reward if helpful

[Former Member]

hi,

TYPE, you assign datatype directly to the data object while declaring.

LIKE,you assign the datatype of another object to the declaring data object. The datatype is referenced indirectly.

Type is a keyword used to refer to a data type whereas Like is a keyword used to copy the existing properties of already existing data object.

type refers the existing data type

like refers the existing data object

[Former Member]

Avoid using 'LIKE', it not compatible with OOPs.

example of type:

• types

types: begin to ty_SO,

vbeln type vbak-vbeln,

erdat type vbak-erdat,

netwr tyep vbak-netwr,

end of ty_so.

• tables

data: ist_so type table of ty_so, " internal table body

wa_so type ty_so. " work area of the table ist_so.

u can use as : loop at ist_SO int wa_so. endloop. etc.

Note: if you want to fire a query like select * form abc into table itab where vbeln in 'AB%'.

means all sales orders starting with 'AB'. Then you need to use 'LIKE'.

reward points, if helpful.

Rgs,

Ashok.

[Former Member]

Hi,

This is an explanation of differences between TYPE and LIKE additions

Additional key words

Data types, data objects, ABAP type concept, Dictionary reference

Cause and prerequisites

The ABAP type concept distinguishes between data types and data objects.

o Data types are either defined locally in an ABAP program with TYPES

or globally in the ABAP Dictionary.

o Data objects reside in the internal mode of an ABAP program and are

declared prototypical with the statement DATA.

When you declare local program data types with TYPES or data objects with

DATA, the data type must be defined. To do this you can refer to already

existing types in addition to using type constructors, for example, TYPE

TABLE OF or TYPE REF TO. It is possible to refer to data types using the

TYPE addition and the data object using the LIKE addition. Furthermore,

type references are possible using TYPE and LIKE also during typing

interface parameters or field symbols.

o TYPE addition

With TYPE addition, you can refer either to local data types of the

same ABAP program or on global data types of the Dictionaries.

Local types mask global types that have the same names. When typing

the interface parameters or field symbols, a reference is also

possible to generic types ANY, ANY TABLE,INDEX TABLE, TABLE or

STANDARD TABLE, SORTED TABLE and HASHED TABLE.

o The LIKE addition

With the LIKE addition, you can refer to all visible data objects

at the ABAP program's positon in question. Only the declaration of

the data object must be known. In this case it is totally

irrelevant whether the data object already exists physically in

memory during the LIKE reference. Local data objects mask global

data objects that have the same name.

The semantic separation between data types and data objects is reflected by

the syntactic separation in ABAP between TYPE and LIKE. This separation

allows for separate namespaces for data types and data objects. Only for

reasons of compatibility with preceding releases, can you refer to flat

structures (see note 176336) in the ABAP Dictionary with the LIKE addition,

so to database tables and independent flat structures. The LIKE addition

first finds a data object on the local program and then in the ABAP

Dictionary it finds a database table or flat structure that has the same

name. The type reference on the ABAP Dictionary is no longer possible with

LIKE in the class of ABAP objects. In all ABAP programs, the LIKE referenceis forbidden on data elements, internal tables and deep structures of the

ABAP Dictionary.

The TYPE reference to global data types of the ABAP Dictionary is possible

as of Release 4.5. At the same time all types of the ABAP type concept can

be defined in the ABAP Dictionary as of Release 4.5. Previously there was

only an actual equivalent for flat structures between the ABAP data types

and the dictionary data types. The structure of database tables and

independent structures corresponded to the ABAP data type structure in the

dictionary Only with the LIKE addition could database tables and structures

be referred to from ABAP programs. In the meantime the LIKE addition should

be used in all ABAP programs only for referring to data objects while the

TYPE addition is used of the reference to the data type.

Caution should be taken if a flat structure is changed in the dictionary by

adding or changing a component into a deep structure. Then a reference with

the LIKE reference is syntactically no longer possible and the ABAP

programs must be changed appropriately. As outlined in Note 176336, such a

structure change means more than replacing the LIKE with the TYPE addition.

Moreover the use of the structure must also be checked at other positions.

Type: It is used when userdefined object link with SAP

system data type.

Like: It is when data object link with the other data

object.

type can be used to create data objects from 1) another

data objects 2) dictionary 3)predifined types. In the same

way like is used to create data objects from another data

objects only, but like will not pass EPC (Extended program

check).

The Statements TYPES and DATA

Each ABAP program define its own data types using the statement.

TYPES dtype TYPE type ...

and declare its own variables or instance attributes of classes using the statement

DATA var {TYPE type} ...

Within the program or a class, you can also define local data types and variables within procedures. Local variables in procedures obscure identically-named variables in the main program or class.

When creating data types and data objects, there are a number of naming convention that also apply for other local program definitions, such as procedures. These are described in detail in the keyword documentation.

The Additions TYPE and LIKE

The additions TYPE type and LIKE dobj are used in various ABAP statements. The additions can have various meanings, depending on the syntax and context.

· Definition of local types in a program

· Declaration of data objects

· Dynamic creation of data objects

· Specification of the type of formal parameters in subroutines

· Specification of the type of formal parameters in methods

· Specification of the type of field symbols

Constructing New Data Types

The TYPE addition allows you to construct new data types in the TYPES, DATA; CONSTANTS; and STATICSstatements. In the TYPES statement, these are local data types in the program. In the other statements, they are attributes of new data objects, meaning that the newly defined data types are not free-standing. Rather, they are linked to database objects.This means that you can refer to them using the LIKEaddition, but not using TYPE.

To construct new data types, the addition TYPE can be used with the following type constructors:

· Construction of reference types

REF TO type|dobj

· Construction of structured data types

BEGIN OF struc_type.

...

END OF struc_type.

· Construction of table types

tabkind OF linetype

These data types only exist during the runtime of the ABAP program.

Referring to Known Data Types or Data Objects

Using the additions TYPE or LIKE in the TYPESstatement, local data types in a program can be referred to known data types or data objects. This is mainly the case with user-defined elementary data types. If you declare variables using the additions TYPE type or LIKE dobj with statement DATA, the data type of var is already fully defined before the declaration is made.

The known types or data that are referred to must be visible at the point where the data type or variable is declared.

A known data type can be any of the following:

· A predefined ABAP type to which you refer using the TYPE addition

· An existing local data type in the program to which you refer using the TYPE addition

· The data type of a local data object in the program to which you refer using the LIKE addition

· A data type in the ABAP Dictionary to which you refer using the TYPE addition. To ensure compatibility with earlier releases, it is still possible to use the LIKE addition to refer to database tables and flat structures in the ABAP Dictionary. However, you should use the TYPE addition in new programs.

The LIKE addition takes its technical attributes from a visible data object. As a rule, you can use LIKE to refer to any object that has been declared using DATA or a similar statement, and is visible in the current context. The data object only has to have been declared. It is irrelevant whether the data object already exists in memory when you make the LIKE reference.

· In principle, the local data objects in the same program are visible. As with local data types, there is a difference between local data objects in procedures and global data objects. Data objects defined in a procedure obscure other objects with the same name that are declared in the global declarations of the program.

· You can also refer to the data objects of other visible ABAP programs. These might be, for example, the visible attributes of global classes in class pools. If a global class cl_lobal has a public instance attribute or static attribute attr, you can refer to it as follows in any ABAP program:

DATA dref TYPE REF TO cl_global.

DATA: f1 LIKE cl_global=>attr,

f2 LIKE dref->attr.

You can access the technical properties of an instance attribute using the class name and a reference variable without first having to create an object. The properties of the attributes of a class are not instance-specific and belong to the static properties of the class.

TYPES: BEGIN OF struct,

number_1 TYPE i,

number_2 TYPE p DECIMALS 2,

END OF struct.

DATA: wa_struct TYPE struct,

number LIKE wa_struct-number_2,

date LIKE sy-datum,

time TYPE t,

text TYPE string,

company TYPE s_carr_id.

This example declares variables with reference to the internal type STRUCT in the program, a component of an existing data object wa_struct, the predefined data object SY-DATUM, the predefined ABAP type t and STRING, and the data element S_CARR_ID from the ABAP Dictionary.

Referring to Generic Data Types

If you refer to one of the generic predefined ABAP types of fixed length (c, n, p, x) in the TYPES or DATA statement, you must specify the undefined technical attributes.

TYPES|DATA var[(length)] TYPE type ...

TYPES|DATA var TYPE type ...

DATA: text1,

text2 LENGTH 2,

text3 TYPE c LENGTH 3,

pack TYPE p DECIMALS 2 VALUE '1.225'.

This example creates three character variables with field lengths of one, two, and three bytes respectively, and a packed number variable with field length 8 bytes and two decimal places. If the attribute Fixed point arithmetic is set, the value of pack is 1.23.

This example shows how to declare elementary data objects with reference to predefined ABAP types.

PROGRAM demo_elementary_data_objects.

DATA text1 TYPE c LENGTH 20.

DATA text2 TYPE string.

DATA number TYPE i.

text1 = 'The number'.

number = 100.

text2 = 'is an integer.'.

WRITE: text1, number, text2.

This program produces the following output on the screen:

The number 100 is an integer.

In this example, the data objects text1, text2 and number are declared with the DATA statement. The technical attributes are determined by referring to the predefined ABAP types c, string, and I. Values from unnamed literals are assigned to the data objects. The contents of the named data objects are displayed on the list.

Specifying a Start Value

When you declare an elementary fixed-length variable, the DATAstatement automatically fills it with the type-specific initial value as listed in the table in the Predefined ABAP Types section.

However, you can also specify a starting value of a fixed-length elementary variable (also within a structure declaration) using the VALUE addition in the DATAstatement:

DATA var ... VALUE val|{IS INITIAL}.

Specifying start values:

DATA: counter TYPE p VALUE 1,

date TYPE d VALUE '19980601',

flag TYPE n VALUE IS INITIAL.

After this data declaration, the character string flag contains its type specific

Initial value ‘0’.

this may help u .

Thanks&regards,

Sravani.