What is the difference between MOVE and WRITE TO ststement?

Question

Hi
What is the difference between MOVE and WRITE TO ststement?
When do we use both of them?
Thank You

Answer 1

Hi,
<b>MOVE</b>
Syntax
MOVE source {TO|?TO} destination.
destination {=|?=} source.
Effect
Both these statements assign the content of the operand source to the data object destination. The variants with the language element TO or the assignment operator = are valid for all assignments between operands that are not reference variables, and for assignments between reference variables for which the static type of source is more specific than or the same as the static type of destination(narrowing cast).
Variants with the language element ?TO or the assignment operator ?= (casting operator ) must be used if the source and destination are reference variables and the static type of source is more general than the static type of destination (widening cast). For assignments between operands that are not reference variables, use of the question mark ? is not permitted.
The data object destination can be any data object that can be listed at a write position, and the data object source can be a data object, a predefined function or a functional method (as of release 6.10). The data type of the data object destination must either be compatible with the data type of source, or it must be possible to convert the content of source into the data type of destination according to one of the conversion rules.
Notes
If source and/or destination are field symbols, then, as in all ABAP commands, the system works with the content of the data objects to which the field symbols point. The actual pointer content of a field symbol can only be changed using the statement ASSIGN or the addition ASSIGNING when processing internal tables (value semantics). If source and destination are reference variables, the reference contained in source is assigned to destination (reference semantics).
Strings and internal tables are addressed internally using references. When assignments are made between strings and between internal tables (as of release 6.10), only the reference is transferred, for performance reasons. After the assignment, the actual string or the actual table body of the source as well as the target object are addressed (sharing). When the object is accessed to change it, the sharing is canceled and a copy of the content is made. The sharing is displayed in the memory consumption display of the ABAP debugger and in the Memory Inspector tool (as of release 6.20).
Obsolete Form: MOVE PERCENTAGE
Exceptions
Catchable Exceptions
CX_SY_CONVERSION_NO_NUMBER
Cause: Operand cannot be interpreted as number
Runtime Error: CONVT_NO_NUMBER (catchable)
CX_SY_CONVERSION_OVERFLOW
Cause: Overflow with arithmetic operation (type P, with specified length)
Runtime Error: BCD_FIELD_OVERFLOW (catchable)
Cause: Operand too large or (intermediate) result too large
Runtime Error: CONVT_OVERFLOW (catchable)
CX_SY_MOVE_CAST_ERROR
Cause: Source or target variable are not reference variables
Runtime Error: MOVE_CAST_REF_ONLY
Non-Catchable Exceptions
Cause: Source field (type P) does not contain correct BCD format.
Runtime Error: BCD_BADDATA
Cause: Assignment for deep structures not permitted if these overlap.
Runtime Error: MOVE_COMPLEX_OVERLAP
Cause: Type conflict with the assignment between object references.
Runtime Error: MOVE_INTERFACE_NOT_SUPPORTED,
Runtime Error: MOVE_IREF_NOT_CONVERTIBLE,
Runtime Error: MOVE_IREF_TO_OREF,
Runtime Error: MOVE_OREF_NOT_CONVERTIBLE
Cause: Type conflict with the assignment between data references.
Runtime Error: MOVE_DREF_NOT_COMPATIBLE
Cause: Assignment between the types involved not supported.
Runtime Error: MOVE_NOT_SUPPORTED
Cause: Constants and literals must not be overwritten.
Runtime Error: MOVE_TO_LIT_NOTALLOWED
Cause: onstants and literals must not be overwritten.
Runtime Error: MOVE_TO_LIT_NOTALLOWED_NODATA
Cause: During a loop in an internal table, an attempt was made to overwrite a reference variable that is linked with the internal table by REFERENCE INTO.
Runtime Error: MOVE_TO_LOOP_REF
<b>Write</b>
Syntax Diagram
WRITE - TO
Syntax
WRITE {source|(source_name)} TO destination
                             [int_format_options].
Effect:
This statement assigns the formatted content of the data object source, or the formatted content of the data object whose name is contained in source_name, to the data object destination. The data objects source_name and destination must be character type and flat. source_name can contain the name of the data object to be assigned in upper or lower case. If the data object specified in source_name does not exist, the assignment is not executed, and sy-subrc is set to 4.
The statement WRITE TO has the same effect as the statement WRITE for lists. This statement formats the content of source or the source field specified in source_name as described in the field. It does not, however, store the result in an output area of a list in the list buffer, but instead stores it in a variable. The output length is determined by the length of the variable.
The same additions int_format_options can be specified for formatting the content as in the statement WRITE for lists, except for NO-GAP and UNDER.
System fields
sy-subrc Meaning
0 The data object specified in source_name was found and the assignment was executed.
4 The data object specified in source_name was not found and the assignment was not executed.
For the static specification of source, sy-subrc is not set.
Note:
If destination is specified as an untyped field symbol or an untyped formal parameter, and is not flat and character-type when the statement is executed, this leads to an untreatable exception in a Unicode program. In non-Unicode programs, this only leads to an exception for deep types. Flat types are handled as character-type data types.
Example:
After the assignment, the variables date_short and date_long receive the current date in the order specified in the user master record. The variable date_long also contains the defined separators, as the output length is sufficiently long. The content of the variable date_mask is formatted according to the formatting addition DD/MM/YY.
DATA: date_short(8) TYPE c,
      date_long(10) TYPE c,
      date_mask(8)  TYPE c.
WRITE sy-datum TO: date_short,
                   date_long,
                   date_mask DD/MM/YY.
Exceptions
Non-Catchable Exceptions
Cause: Negative length specified for offset/length
Runtime Error: WRITE_TO_LENGTH_NEGATIVE
Cause: Negative offset specified in offset/length
Runtime Error: WRITE_TO_OFFSET_NEGATIVE
Cause: Offset specified in offset/length specification is longer than the field length.
Runtime Error: WRITE_TO_OFFSET_TOOLARGE
Thanks
sunil