ABAP Keyword Documentation → ABAP − Reference → Processing Internal Data → Numeric Calculations
+=, -=, *=, /= - Calculation Assignments
Other versions: 
 7.31 | 7.40 | 7.54
Syntax
lhs += 
  | -= 
  | *= 
  | /= rhs.
Effect
Calculation assignment with the
- addition assignment operator 
+= 
- subtraction assignment operator 
-= 
- multiplication assignment operator 
*= 
- division assignment operator 
/= 
These assignments have the same function as the following assignments of arithmetic expressions:
lhs = lhs + ( rhs ).  
lhs = lhs - ( rhs ).  
lhs = lhs * ( rhs ).
 lhs = lhs / ( rhs ).
The content of lhs
- 
has the result of the parenthesized expression 
rhsadded to it, - 
or has the result of the parenthesized expression 
rhssubtracted from it, - 
or is multiplied by the result of the parenthesized expression 
rhs, - 
or is divided by the result of the parenthesized expression 
rhs, 
and the result is assigned to lhs. The
calculation type is determined accordingly.
The following applies to the operands lhs and rhs:
- 
lhsis a result position and the following can be specified (if numeric): 
- 
rhsis a numeric expression position and the following can be specified (if numeric): 
# is not currently possible in constructor expressions.
Character-like expressions and
bit expressions cannot be specified.
Division by the value 0 is undefined and raises a handleable exception. The only situation where division by 0 does not raise an exception is if the dividend is also 0. Here, the result is set to 0.
Notes
- 
Alongside data objects, calculation assignments also allow expressions in the operand positions. This
makes them more powerful than the statements 
ADD,SUBTRACT,MULTIPLY,DIVIDE, and also makes these statements obsolete. - 
No inline declarations are possible for 
lhs. - 
Calculation assignments can currently only be specified as standalone statements. They cannot be used
in expressions, for example after 
NEXTin reduction operatorREDUCE. - 
See also the concatenation assignment operator
(
&&=). 
Example
The variable n has the value 1.50 after the calculation assignments.
DATA n TYPE p DECIMALS 2. 
n += 1. 
n += 1. 
n += 1. 
n += 1. 
n -= 2. 
n *= 3. 
n /= 4.