Data item functions are elementary data items and return alphanumeric,

national,

numeric or integer values. Data item functions are treated as elementary data items and cannot be receiving operands. The types of data item functions are:

- Alphanumeric functions. These are of the class and category alphanumeric. The number of character positions in this data item is specified in the function definition. Alphanumeric functions have an implicit usage of DISPLAY.
- Numeric functions. These are of the class and category numeric. A numeric function is always considered to have an operational
sign.
- A numeric function can be used only in an arithmetic expression
or as the source of a MOVE statement

- A numeric function cannot be referenced where an integer operand is required, even though a particular reference can yield an integer value.

- A numeric function can be used only in an arithmetic expression
- Integer functions. These are of the class and category numeric. An integer function is always considered to have an operational
sign.
- An integer function can be used only in an arithmetic expression
or as the source of a MOVE statement

or anywhere an integer data item is not used as a receiving data item.

- An integer function can be referenced where an integer operand is required and where a signed operand is allowed.

- An integer function can be used only in an arithmetic expression
- National functions. These are of the class and category national. The number of character positions in this data item is specified in the function definition. National functions have an implicit usage of NATIONAL.