When I create a class, I receive “illegal start of type” error in “try-catch” block

Question

class address
{

String address;
String newaddr = address.trim();
final int ziplength =4;
    String input;
    Scanner in = new Scanner(System.in);
    String temp          


        

Answer 1

class address
{
    String address;
    String newaddr = address.trim();
    final int ziplength =4;
    String input;
    Scanner in = new Scanner(System.in);
    String temp = in.next();
    String zipcode = input.substring(input.length()-ziplength);
public address() //this is the only thing I add, but it eliminate "illegal start type error"
        {
    try 
    {
        Integer.parseInt(zipcode);
        System.out.println("PO is: "+zipcode);    
    }
    catch( Exception e) 
    {
        System.err.println("Last 4 chars are not a number.");
    }
        }
}

Special thank you for @Jägermeister . He gives me valuable hint.

Since I am a beginner, I am thinking a better way to improve my skills. I will try more.