What these are valid brackets?

Question

1.({ #i don't know
2.)} #i don't know
3.{()} # valid
what 1 and 2 are valid or not.tell me.

Answer 1

well if a bracket or parenthesis or braces will get their opening and closing pair then they are valid it's evaluated from most inner to outer so 1 and 2 statement didn't get any match so that are not valid
3 one is valid because first innermost part is evaluate and it's in pair and then outer part evaluate which is also in pair so it's valid
{ opening ( opening closing ) closing } so one which open is closed to so it is valid

Answer 2

1 & 2 aren't valid.

Note: your question is posted 2 times, please delete unanswered one.