public class Example {
    String str = new String("good");
    char[] ch = { 'a', 'b', 'c' };

    public static void main(String args[]) {
        Example ex = new Example();
        ex.change(ex.str, ex.ch);
        System.out.print(ex.str + " and ");
        System.out.print(ex.ch);
    }

   public void change(String str, char ch[])       
   {
        str = "test ok";
        ch[0] = 'g';
    }
}

• good and abc
• good and gbc
• test ok and abc
• test ok and gbc