here is an example
The three parameters condition, then and else are all expressions. The first one, condition, is interpreted logically. The two other ones, then and else, can be of any type. They should preferably be of the same type. If condition is true, the function returns the value of the expression then. If condition is false, the function returns the value of the expression else.
if( Amount>= 0, 'OK', 'Alarm' )