I have some Integers inside of an ArrayList
ArrayList<Integer> al = new AraayList<Integer>();
al.add(100);
al.add(211);
Now I want to split the values in the ArrayList into an array. Suppose 100 is the first value in the ArrayList then the corresponding array should contain 1, 0, 0
If you are using Java 8+ you can use streams with this trick :
List<Integer> result = al.stream()
.map(String::valueOf)
.flatMap(s -> Arrays.stream(s.split("")))
.map(Integer::valueOf)
.collect(Collectors.toList());
Details
.map(String::valueOf) this will convert your Integer to String eg. 100 => "100".flatMap(s -> Arrays.stream(s.split(""))) this will create a Stream by the split with "" eg. "100" => ["1", "0", "0"].map(Integer::valueOf) this will parse each String to Integer eg. ["1", "0", "0"] => [1, 0, 0].collect(Collectors.toList()); this will collect all the result in a list eg. [1, 0, 0, 2, 1, 1]
You can run through the each element in a for loop or foreach since Java 8. Then in the loop you could convert it to a String with
yourNumberAsString = String.valueOf(yourNumberInArray);
With
yourNumberAsString.charAt(0);
you get the position of the first digit, with 100 it would be 1. If you do that dynamically in another for loop your work is done.
You can iterate over the array, convert the Integer in String and use Split method to get String array:
for(int i=0; i < al.size(); i++)
{
String [] array = al[i].toString().split("");
// do whatever you need with the array
}
