I am trying to make java go trough a list of numbers. It chooses the first one, gives this as output, waits/sleeps like 2000 milliseconds and then give the next one as output, waits 2000 milliseconds, etc.
They should not be listed behind eachother so when my list is: 10 20 30 40 50
It should not give as output: 10 20 30 40 50. But just 50.
It would be even better if it was able to repeat itself.
So far i tried:
List<Integer> myCoords = new ArrayList<Integer>();
myCoords.add(10);
myCoords.add(20);
myCoords.add(30);
myCoords.add(40);
myCoords.add(50);
Iterator<Integer> myListIterator = someList.iterator();
while (myListIterator.hasNext()) {
Integer coord = myListIterator.next();
}
But this has no timer, and i am not sure if this will only show '20' or '10 20 30 40 50' as output. And i dont really know how to put a sleep/wait command and a repeat command in this :s (might have overlooked the repeat command if its already in)
Edit Tyvm all, i can go on with the rest of the coding now :)
5 Answers
If you want to rewrite a line on console, print a control character \r (carriage return).
List<Integer> myCoords = new ArrayList<Integer>();
myCoords.add(10);
myCoords.add(20);
myCoords.add(30);
myCoords.add(40);
myCoords.add(50);
Iterator<Integer> myListIterator = myCoords.iterator();
while (myListIterator.hasNext()) {
Integer coord = myListIterator.next();
System.out.print("\r");
System.out.print(coord);
Thread.sleep(2000);
}
code that works, but output is:
10
20
30
40
50
so:
List<Integer> myCoords = new ArrayList<Integer>();
myCoords.add(10);
myCoords.add(20);
myCoords.add(30);
myCoords.add(40);
myCoords.add(50);
for (Integer number : myCoords) {
System.out.println(number);
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
To insert a sleep command you can use Thread.sleep(2000). So the code would be:
List<Integer> myCoords = new ArrayList<Integer>();
myCoords.add(10);
myCoords.add(20);
myCoords.add(30);
myCoords.add(40);
myCoords.add(50);
Iterator<Integer> myListIterator = someList.iterator();
while (myListIterator.hasNext()) {
Integer coord = myListIterator.next();
System.out.println(coord);
Thread.Sleep(2000);
}
This would output: 10 20 30 40 50
If you want the numbers after each other you could use: System.out.print(coord +" " ); and if you want to repeat the section you can put it in another while loop.
List<Integer> myCoords = new ArrayList<Integer>();
myCoords.add(10);
myCoords.add(20);
myCoords.add(30);
myCoords.add(40);
myCoords.add(50);
while(true)
Iterator<Integer> myListIterator = someList.iterator();
while (myListIterator.hasNext()) {
Integer coord = myListIterator.next();
System.out.print(coord + " ");
Thread.Sleep(2000);
}
}
This would output: 10 20 30 40 50 10 20 30 40 50 ... and never stop until you kill the program.
Edit: You do have to put the sleep command in a try catch block
Let's use some java 8 feature:
IntStream.iterate(10, x -> x + 10).limit(5)
.forEach(System.out::println);
If you need to store the numbers you can collect them into a collection eg:
List numbers = IntStream.iterate(10, x -> x + 10).limit(5)
.boxed()
.collect(Collectors.toList());
And some delay added:
IntStream.iterate(10, x -> x + 10).limit(5)
.forEach(x -> {
System.out.println(x);
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
// Do something with the exception
}
});
So it would become:
List<Integer> myCoords = new ArrayList<Integer>();
myCoords.add(10);
myCoords.add(20);
myCoords.add(30);
myCoords.add(40);
myCoords.add(50);
while(true)
Iterator<Integer> myListIterator = myCoords.iterator();
while (myListIterator.hasNext()) {
Integer coord = myListIterator.next();
System.out.print("\r" + coord);
try{
Thread.sleep(2000);
}catch(Exception e){
// handle the exception...
}
}
}
