Jessica, Vector is a legacy class. You should now use ArrayList class. ArrayList stores elements in an underlying array. The system will default the size for you. The system then manages the underlying array. If you add elements to the ArrayList and the underlying array is full the system creates a new larger underlying array and copies the old underlying array to the new underlying array. There are some slight performance issue in adding and deleting from the middle of the list. If you have a rough guess of the size the ArrayList should be, set it slightly larger. Too large and you waste space to small and the system will have to create a new array that is larger to handle the ArrayList expanding. Size of ArrayList is a concern if performance is an issue.
The lessons on Java Collections Framework. -> Exercise 2: Build and run applications that use "List" Collection objects (30 minutes)-> Build and run an application that uses ArrayList These lessons show how to work with ArrayList. If you are working with legacy code that requires Vector class I think it is similar to ArrayList. Keith ________________________________ From: Jessica Sun <[email protected]> To: [email protected] Sent: Wednesday, February 25, 2009 7:04:34 AM Subject: [java programming] Pls Share ur experience with Java Vector Dear all, Discussions about Vector in JAVA vector is like an array, but it grows as necessary to allow you to add as many elements as you like. So it becomes very handy when you program something with unknown number. Here are my questions If I want to vector instead of an array , the type of array will be double, how should I implement it. See example below double Jarray [] = new double [100] ; double KTarray [] = new double [100] ; double m_dHigh, m_dStep, Jrange; int Ni; …. for( Ni=0; Jrange<=m_dHigh+0.00000001; Ni++){ Jarray[Ni]=Jrange; ( Some methods here) KTarray[Ni]=KTT; Jrange=Jrange+m_dStep; } In this code I want to use Vector Jarray instead of Jarray[] and KTarray[]; Please if you have time come up with your ideas, and any literature of how to use Vector are welcome! Thanks in advance Best Regards Js (a new user of java ) --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/javaprogrammingwithpassion?hl=en -~----------~----~----~----~------~----~------~--~---
