firstWhere method
- bool test(
- E value
- {E orElse(
override
The first element that satisfies the given predicate test
.
Iterates through elements and returns the first to satisfy test
.
Example:
final numbers = <int>[1, 2, 3, 5, 6, 7];
var result = numbers.firstWhere((element) => element < 5); // 1
result = numbers.firstWhere((element) => element > 5); // 6
result =
numbers.firstWhere((element) => element > 10, orElse: () => -1); // -1
If no element satisfies test
, the result of invoking the orElse
function is returned.
If orElse
is omitted, it defaults to throwing a StateError.
Implementation
E firstWhere(bool test(E value), {E Function()? orElse}) {
for (E element in this) {
if (test(element)) return element;
}
if (orElse != null) return orElse();
throw IterableElementError.noElement();
}