How to split a List<String > values and get only numbers into another list

Question

I am having List values as ["12-dept20","13-dept50"] i want to split these to a list with only the numbers before - , to get a List as [12, 13]

List. split using streams , but not sure on how to work on it. Any help would be appreciated. I am using java 8

List src = ["12-dept20","13-dept50"];

Expected:

List new = [12, 13]

Answer 1

Here you go:

List<String> source = List.of("12-dept20", "13-dept50");

List<Integer> target = source.stream()
        .map(entry -> entry.split("-")[0])
        .map(Integer::valueOf)
        .toList();

System.out.println(target);

Bear in mind that this code is not failsafe, in case the entries cannot be parsed due to missformat.