Why is this an issue?
Generally it’s not recommended to modify a collection while it’s iterated and most JDK collection implementations don’t support it. This may
sometimes lead to a ConcurrentModificationException and it could be the source of incorrect or unspecified behaviors in the code.
This rule raises an issue when a method modifies the size of a collection, while the same collection is iterated.
Noncompliant code example
public static void foo(List<String> lst) {
for (String element : lst) {
if (element.startsWith("x")) {
lst.remove(element); // Noncompliant: lst size has been modified by "remove" call while it's iterated.
}
}
}