List contactGroups = ['b','c','d']
List displayContactGroupList = ['a']
displayContactGroupList << contactGroups
I was expecting that at the end of the execution, I will have
displayContactGroupList = ['a', 'b','c','d' ]
However, I was surprised to find that the value was
displayContactGroupList = ['a', ['b','c','d'] ]
Learned a new thing today, So to get the effect of what I wanted to get, I will have to use
displayContactGroupList.addAll(contactGroups)
