See this code:
Code: Select all
try{
x:=a
}catch UnsetError{
x:=0
}
Therefore, the other nearly the same code, should be replaced by x:={}.a??0 too.
Code: Select all
try{
x:={}.a
}catch UnsetError{
x:=0
}
It's worth mentioning that ?? can only ignore the exception which is near ??. For example, x:=myVar.a??0, in this situation, ?? can only handle a but can not handle myVar if myVar is also unset.