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toArray() of ArrayList<String>

843793Jul 18 2004 — edited Jul 18 2004
   ArrayList<String> relNames;

   public String[] getRelNames()
   {
      if (database == null)
         throw new Error("No database is connected.");
     else
        return relNames.toArray();
   }
the code above wont compile because relNames.toArray(); returns Object[], but i ve specified in the declaration that ArrayList<String> relNames; dont quite understand why?

Comments

843793
the code above wont compile because
relNames.toArray(); returns Object[], but i ve
specified in the declaration that ArrayList<String>
relNames; dont quite understand why?
Object[] toArray() doesn't utilize generics. It always returns an array of Objects.

This should work. 
ArrayList<String> relNames;

public String[] getRelNames()
{
   if (database == null)
      throw new Error("No database is connected.");
   else
      return relNames.toArray(new String[] {});  //use <T> T[] toArray(T[])
}
843793
Of course, if you had 
ArrayList<T> relNames;
You will have to find a different solution. You can't create generic arrays.
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Post Details

Locked on Aug 15 2004
Added on Jul 18 2004
#generics
2 comments
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