Offset data and attribute

Offset data is used exclusively with area variables. The value of an offset variable indicates the location of a based variable within an area variable relative to the start of the area.

Because the based variables are located relatively, if the area variable is assigned to a different part of main storage, the offset values remain valid.

Offset variables do not preclude the use of pointer variables within an area.

The association of an area variable with an offset variable is not permanent. An offset variable can be associated with any area variable by means of the POINTER built-in function (see Locator conversion). The advantage of making such an association in a declaration is that a reference to the offset variable implies reference to the associated area variable. If no area variable is specified, the offset can be used as a locator qualifier only through use of the POINTER built-in function.