Java tutorial
class Gen<T> { T ob; // declare an object of type T Gen(T o) { ob = o; } T getob() { return ob; } } class RawDemo { public static void main(String args[]) { Gen<Integer> iOb = new Gen<Integer>(88); Gen<String> strOb = new Gen<String>("Generics Test"); Gen raw = new Gen(new Double(98.6)); double d = (Double) raw.getob(); System.out.println("value: " + d); strOb = raw; // OK, but potentially wrong raw = iOb; // OK, but potentially wrong } }