ABAP Keyword Documentation → ABAP − Reference → Processing Internal Data → Assignments → =  Assignment Operator → =  Assign Calculation Expressions
=, Arithmetic Expression
Other versions:
7.31  7.40  7.54
Syntax
result = arith_exp.
Effect
If an arithmetic
expression arith_exp
is specified on the right side of the assignment operator =
, its
calculation type is calculated and assigned to the left side result
.
The following can be specified for result
:
 A variable compatible with the numeric result of the arithmetic expression or to whose type the result can be converted.

An inline declaration
DATA(var)
. The data type of the declared variablevar
is the statically known calculation type, where generically typed field symbols and formal parameters are respected using a standard type described there. In the case of the calculation type p, the data type of the declared variable is alwaysp
with the length 8 without decimal places.
If an existing variable is specified for result
, its data type is respected when determining the
calculation type. If the calculation type is not the data
type of result
, the result is converted to the data type of the result field before the assignment is made.
Notes
 The fact that the result field is respected when the calculation type is determined is a special property of ABAP that should always be kept in mind.
 The calculation type that is dependent on the data type of the result field is a major different from an assignment of data objects; if data objects are incompatible, the source field is always converted to the data type of the target field. When arithmetic expressions are assigned, their operands can also be converted to the data type of the result field before the calculation.

The fact that a calculation
type
p
on the right side of an inline declaration produces the data typep
with length 8 and no decimal places can produce unexpected results and raise exceptions. It is best to either avoid inline declarations when using the calculation type p or to determine the data type by applying the conversion operatorCONV
to the arithmetic expression. 
See also calculation
assignments with the operators
+=
,=
,*=
und/=
.
Example
The first assignment is an assignment of an arithmetic expression, because of its sign. The
calculation type is determined as i
and result
is given the value "731036", the number of days since 01.01.0001. The second assignment, on the other hand, has the same meaning as an
assignment of data objects and produces the value "20020704" in result
.
DATA: result TYPE string,
date TYPE d VALUE '20020704'.
result = + date.
result = date.
Example
This example demonstrates inline declarations with the calculation type p
.
Assignments of a data object use its data type, but assignments of an arithmetic expression with the
calculation type p
of the data type p
with length
8 and without decimal places. This means that decimal places are lost in the first assignment and that
the second assignment produces and overflow and its corresponding exception. The conversion operator CONV
can be used to bypass these problems.
TYPES pack8_3 TYPE p LENGTH 8 DECIMALS 3.
TYPES pack16 TYPE p LENGTH 16.
DATA number1 TYPE pack8_3 VALUE '12345.6789'.
DATA number2 TYPE pack16 VALUE '12345678901234567890'.
DATA(result1) = number1. "p, length 8, decimals 3
DATA(result2) = number2. "p, length 16
TRY.
DATA(result3) = 1 * number1. "p, length 8, decimals 0
DATA(result4) = 1 * number2. "p, length 8 >exception
CATCH cx_sy_arithmetic_overflow.
ENDTRY.
DATA(result5) = CONV pack8_3( 1 * number1 ). "p, length 8, decimals 3
DATA(result6) = CONV pack16( 1 * number2 ). "p, length 16