import java.util.Vector;


public class Main{
   public static void main(String[] args){
      Vector <Integer>[] fool;
      foo=new Vector[5];
      foo[0]=new Vector<Integer>();
      foo[1]=new Vector<String>();
   }
}

COMPILE ERROR:

D:\Documents and Settings\ssta\Scratch\src\scratch\Main.java:11: incompatible types
found   : java.util.Vector<java.lang.String>
required: java.util.Vector<java.lang.Integer>
      foo[1]=new Vector<String>();
Note: D:\Documents and Settings\ssta\Scratch\src\scratch\Main.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
1 error
BUILD FAILED (total time: 0 seconds)