Group or group? in rules

Setup, Configuration and Use Scripts & Rules
1

Hello,

Reading documentation and samples I have found different ways to use groups. In some of the samples (f.e at Check presence by detecting WiFi phones/tablets) the group is used as group.members..., but in other (f.ex. at this code) as group?.members.... Which is the correct one?

2

Both are correct. The one with the ‘?’ is a shorthand for:

if(group != null) {
    group.members...
}