我如何每天一次遍历数组？

Question

So I'm working on an application that needs to display a value, a specific string of text once per day. I have all my strings in an array and now I just need a way to increase the index once per day. The kicker is that if the user downloads the application later in the year I need to have all the other days accounted for. So basically the user will see the same tip as a person who downloaded the app on the first day. Any suggestions?

Would using the Calendar class be my best bet? I just don't want to set an individual switch and case for every day of the year.

Answer 1

if I understand you correctly (Bob downloaded the app a hundred days ago should see the same tip as Alice who downloaded the application today), you can use Calendar's DAY_OF_YEAR value to display the same date

    Calendar ca1 = Calendar.getInstance(); //get today's date

    int DAY_OF_YEAR=ca1.get(Calendar.DAY_OF_YEAR) -1; //DAY_OF_YEAR starts at one

    //avoid IndexOutOfBoundsExceptions
    String tip = tiparray[DAY_OF_YEAR % tiparray.length]; 

Answer 2

Not sure if I understand completely the question. I think you will need to have the same tip shown for everyone in each day, right?

If so, you can use Calendar.DAY_OF YEAR :

Calendar cal = Calendar.getInstance();
int index=cal.get(Calendar.DAY_OF_YEAR);