Suspicious 'List.remove()' in loop

Reports list.remove(index) calls inside an ascending counted loop.

This is suspicious as the list becomes shorter after the removal, and the next element gets skipped. A simple fix is to decrease the index variable after the removal, but probably removing via an iterator or using the removeIf() method (Java 8 and later) is a more robust alternative. If you don't expect that remove() will be called more than once in a loop, consider adding a break after it.

Example:

public static void main(String[] args) {
  process(new ArrayList<>(
    Arrays.asList("1", "2", "|", "3", "4")));
}

static void process(List<String> list) {
  for (int i = 0; i < list.size(); i++) {
    if (list.get(i).equals("|")) {
      list.remove(i);
      continue;
    }
    System.out.println(list.get(i));
  }
}

The code looks like 1 2 3 4 is going to be printed, but in reality, 3 will be skipped in the output.

New in 2018.2

Inspection Details
Available in:	IntelliJ IDEA 2023.3, Qodana for JVM 2023.3
Plugin:	Java, 233.SNAPSHOT

Last modified: 13 July 2023