Question

Let’s say I have this array

int[] anArray = {
100, 200, 300};

Now, I want everytime my program execute it prints the next element in order.
For example, first time I execute java myProgram, the program print the first element “100”.
For second time I execute the program, it will print the second element “200”.
and so on.
But the forth time, it will repeat itself. and print the first element again.

I imagine, I could save the last element that I print. But I didn’t know how.
Any ideas?

Answer 1

As people here suggested, you should save in an external file the current index, and reset it when reaching the last index. Here is an example code that might help you:

private static final String FILE_NAME = "indexFile";
private static int[] anArray = { 100, 200, 300};

public static void main(String args[]) throws IOException {
    System.out.println(anArray[getIndex()]);

}

private static Integer getIndex() throws IOException {
    BufferedReader in = new BufferedReader(new FileReader(FILE_NAME));
    int index = Integer.parseInt(in.readLine());
    in.close();

    Integer newIndex = (index >= anArray.length - 1) ? 0 : index + 1;
    Writer out = new OutputStreamWriter(new FileOutputStream(FILE_NAME));
    out.write(newIndex.toString());

    out.close();
    return index;
}

When you write your code, you should add validation that the file exists etc.