elementAtOrNull method
- int index
The element at position index
of this iterable, or null
.
The index
is zero based, and must be non-negative.
Returns the result of elementAt(index)
if the iterable has
at least index + 1
elements, and null
otherwise.
Implementation
T? elementAtOrNull(int index) {
RangeError.checkNotNegative(index, "index");
if (this is EfficientLengthIterable) {
if (index >= length) return null;
return elementAt(index);
}
var iterator = this.iterator;
do {
if (!iterator.moveNext()) return null;
} while (--index >= 0);
return iterator.current;
}