Condition

The writing of a condition is the following

@Event('start') 
start() {
    > How old are you ?
    Prompt()
    if (:text > 18) {
        > You are major
    }
    else if (:text < 18) {
        > You are a minor
    }
    else {
        > You are 18 years old
    }
}

Keywords

To verify that a value is either undefined or null, use the keyword unknown

foo(options) {
    if (unknown options) {
        > options are empties
    }
}

Otherwise, to verify that a value is different from undefined or null, let's use the keyword defined

foo(options) {
    if (defined options) {
        > thanks
    }
}

Note that these keywords must be at the beginning of the condition, we can not do true && defined options