Structuring Data with Java - Java - page 239

System . out . println ( "Retrieving by index:" );
for

for ( int int i = 0 ; i < al . size (); i ++) {

System . out . println ( "Element " + i + " = " + al . get ( i ));

}

}

}

The older Vector and Hashtable classes predate the Collections framework, so they provide
additional methods with different names: Vector provides addElement() and elementAt() .
You will see these in legacy code, but you should use the Collections methods add() and
get() instead. Another difference is that the methods of Vector are synchronized, meaning
that they can be accessed from multiple threads (see Synchronizing Threads with the syn-
chronized Keyword ) . This does mean more overhead, though, so in a single-threaded applic-
ation it is usually faster to use an ArrayList (see timing results in Program: Timing Com-
parisons ) .

There are various conversion methods. Table 7-2 mentions toArray() , which will expose
the contents of a List as an array. The java.util.Arrays class features an asList() meth-
od, which converts in the other direction, from an array to a List . With the Variable Argu-
ments feature of modern Java (described in Variable argument lists ), you can create and pop-
ulate a list in one call to Arrays.asList() . For example:

// ArraysAsListDemo.java
List < String > firstNames = Arrays . asList ( "Robin" , "Jaime" , "Joey" );

In days of yore, you needed to be more explicit, like so:

List < String > lastNames =
Arrays . asList ( new new String []{ "Smith" , "Jones" , "MacKenzie" });

Java does indeed get less verbose as time goes by!