# Function column

A custom function column can be used to perform basic arithmetic functions.

It can operate on the following column types:

- Number
- Number with decimals
- Date
- Date and time
- Time spent
- Other function columns

The definition is:

- Supports addition (+), subtraction (-), multiplication (*), division (/).
- Returns number with decimals
- Is read only
- Can't have default values
- Can't inherit

Values in a function column are calculated automatically based on an function input set on the column.

A function uses the following syntax; '(column name) (operator) (column name)... (operator) (column name)'. It is possible to have calculations using multiple columns. Parentheses are used determine order of calculation in the case of multiple columns ( (A + B)/C ).

Multiple functions can use the same input columns.

One function column can use the output from another function column as input. Hansoft checks for calculation loops.

Function columns can be used in dashboards as normal numerical columns.

Date columns can only be used in subtraction with another date column in order to generate a number. The resulting interval is a number and can be used as input to a larger function.

Example: ("Date1" - "Date2") * "Input Column 1"

Limitations:

- Last updated on is not available for calculations as that would create a loop (updates the item, calculates updates etc).
- Aggregated values can't be used as input.
- Can't be copied across projects