Routines (alphabetical) > Object Classes > Miscellaneous Object Classes > IDL_Object::_overloadPlusPlus

# IDL_Object::_overloadPlusPlus

The IDL_Object::_overloadPlusPlus procedure method defines the behavior of the increment (++) operator for instances of objects that inherit from the IDL_Object class.

Object classes that inherit from the IDL_Object class but that do not override this method will throw an error if you attempt to use the ++ operator.

## Example

For an example of how to implement this method, see the BigInteger class in the file `lib/datatypes/biginteger__define.pro` in your IDL installation.

## Syntax

In most cases, this method is called indirectly by specifying an object reference as an argument on either the left or right side of the ++ operator. When called explicitly, the syntax is:

Obj->[IDL_Object::]_overloadPlusPlus

## Arguments

None

## Keywords

None

## Routine Signature

To overload the ++ operator for an object class, implement a method with the following signature:

PRO class::_overloadPlusPlus

Inside this method you should write code that defines the increment operator for your class.

Note: There are two different forms of the increment operator: pre-increment (++a) and post-increment (a++). See the IDL_Object::_overloadPostIncrementCopy method for details on how to handle the two forms.

## Version History

8.4.1 | Introduced

## See Also

IDL_Object::_overloadMinusMinus, IDL_Object::_overloadPostIncrementCopy, Increment/Decrement operators