Why can converticity type 'string' to 'int'?

Answer 1

I think in C#, the best way is to use Int32.TryParse() method. It gives you an option to safely handle invalid values, without writing an extra try-catch block.
https://docs.microsoft.com/en-us/dotnet/api/system.int32.tryparse?view=netframework-4.8

Answer 2

Java has a method: Integer.valueOf:
Integer.valueOf("100") -> 100
does C# have similar?
Or did you ask for something else?

Answer 3

I believe no.
Char to int sure.
String to int[] sure.