# Integer expressions

This section covers integer expression evaluation rules.

An integer expression evaluates to a whole number.

```
MAIN
DEFINE r, c INTEGER
LET c = 4
LET r = c * ( 2 + c MOD 4 ) / getRowCount("customers")
END MAIN
```

The operands of an integer expression can be:

- An integer literal.
- A variable or constant of type
`TINYINT`

,`SMALLINT`

,`INTEGER`

or`BIGINT`

. - A function returning a single integer value.
- A boolean expression.
- The result of a
`DATE`

subtraction, as a number of days.

If an integer expression includes an operand whose value is not an integer data type, the runtime system attempts to convert the value to an integer following the data conversion rules.

If an element of an integer expression is `NULL`

,
the expression is evaluated to `NULL`

.