Local variable in Java with the same name as a global variable

Question

I'm trying to understand scope in Java. In Perl, I can do the following:

my $x = 1;
{
    my $x = 2;
    say $x; # prints 2
}
say $x; # prints 1

In other words, since I declared the variable $x with my within the scope, the $x variable in that scope is local to that scope (i.e., not the same variable as the global $x variable). Now, in Java I am trying to do something similar, but I am getting the error

Variable rawURL is already defined in method run()

Here's the code:

// Global rawURL
URI rawURl;
try {
  rawURL = new URI("http://www.google.com");
} catch (Exception e) {
  // Handle later
}

// Some time later
for (Element link : links) {
  // rawURL in this scope
  URI rawURL;
  try {
    rawURL = new URI(link.attr("abs:href"));
  } catch (Exception e) {
    // Handle later
  }
}

Now, the thing is, I don't want to have to get creative for all of my variable names, ensuring each one is different. I am simply using rawURL to build a normalized URL, so it's essentially a temporary variable. I could just do this:

for (Element link : links) {
  rawURL = new URL(..);
}

But then that will change the contents of my global variable, and I really don't want that. Is there any way to use the same name for the local variable as I am using for the global variable?

Answer 1

You must define a new local variable with a new name because scope of variable is like: current block + subblocks. So in your case, rawURL is defined for what you called "global" and it is visible to subblocks, ie into the for block.

In java, you can do :

{
   String myvar = "";
}

{
   String myvar = "";
}

because here, there are two different blocks at same level

but you can't do :

String myvar = "";
{
    String myvar = "";
}

because there is conflict with same name for two variables in same block (the subblock).