java just curly braces

Question

I was reading a book and there were a few example with programs that has just curly braces

for example

 public static void main(String args[]){
     //what is the uses of curly braces here.
     {
          //some code
     }
 }

Answer 1

It's a code block. The variables declared in there are not visible in the upper block (method body outside of these curlies), i.e. they have a more limited scope.