forEachIndexed method
Performs the given action
on each element, providing sequential index with the element.
@param action
function that takes the index of an element and the element itself
and performs the desired action on the element.
Implementation
void forEachIndexed(void Function(int index, T element) action) {
var index = 0;
for (final item in iter) {
action(index++, item);
}
}