if-then-else

Description

If-then-else expressions almost resemble normal, spoken English. You use them to tell atfinity that if a condition is met then do this, else do that.

The expression can also contain as many elif condition then expression parts as you like. The expression closes with the keyword end.

The if-then-else expression is most often used dealing with calculated information.

Syntax

if [condition] then 
[expression]
elif [condition] then
[expression]
else
[expression]
end

• condition needs to evaluate to true or false. It could be a comparison (p.age >= 18) or a boolean yes/no question (p.has_insurance).

• Both expressions have to return the same type of value, for example a number.

If you have some programming experience, you may be surprised that the else is not optional. Please note though, that if in atfinity is an expression, so it always needs to return a value.

Example

p is Person
if p.loves_danger then high_risk else low_risk end

To determine the risk level of a person, inquire whether it is true or false that the person loves danger.

• True: the expression returns what's behind then: the person is deemed of high risk level.

• False: the expression returns what's behind else: the person's risk level is marked as low.

Example with elif

holiday is Holiday
if holiday.weather = sunshine then 
    'beach' 
elif holiday.weather = rain then 
    'museum' 
elif holiday.budget > 1000 then 
    'restaurant' 
else 
    'home'
end