java 1.4 和 1.5 的差別

Java 1.5 has many new features, compare to Java 1.4. See the link for a complete explanation. Some of the features are:

• Generics (e.g. typed collections, like Set)
• Enhanced for loop (for (String s : set) {...})
• Autoboxing/unboxing (automatically convert between types like Integer to int and vice versa)
  Before Java 5
  
  int intPrimitive = intObject.intValue();
  intPrimitive++;
  intObject = new Integer(intPrimitive);
  
  Using Java 5
  
  Integer intObject = new Integer(10);
  intObject++;
  
  
• Typesafe enums (enum is now a keyword, types can be created out of enums)
• Varargs (for printf() function, allows variable number of arguments)
• Static import (can now import static methods of a class, such as java.lang.Math)
• Annotations