Java: over-typed structures? To have many types in Object[]?

Posted by HH on Stack Overflow See other posts from Stack Overflow or by HH
Published on 2010-05-06T21:05:28Z Indexed on 2010/05/06 21:18 UTC
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Term over-type structure = a data structure that accepts different types, can be primitive or user-defined.

I think ruby supports many types in structures such as tables. I tried a table with types 'String', 'char' and 'File' in Java but errs.

  1. How can I have over-typed structure in Java?
  2. How to show types in declaration? What about in initilization? Suppose a structure:

          INDEX    VAR      FILETYPE
            //0 -> file     FILE
            //1 -> lineMap  SizeSequence
            //2 -> type     char
            //3 -> binary   boolean
            //4 -> name     String
            //5 -> path     String
    

Code

import java.io.*;
import java.util.*;

public class Object
{
        public static void print(char a)
        {
                System.out.println(a);
        }
        public static void print(String s)
        {
                System.out.println(s);
        }

        public static void main(String[] args)
        {
                Object[] d = new Object[6];
                d[0] = new File(".");
                d[2] = 'T';
                d[4] = ".";

                print(d[2]);
                print(d[4]);
        }
}

Errors

Object.java:18: incompatible types
found   : java.io.File
required: Object
        d[0] = new File(".");
               ^
Object.java:19: incompatible types
found   : char
required: Object
        d[2] = 'T';
               ^

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