# firstWhere method

E firstWhere (bool test(E element), { E orElse() })

Returns the first element that satisfies the given predicate `test`.

Iterates through elements and returns the first to satisfy `test`.

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 element), {E orElse()}) {
      int length = this.length;
      for (int i = 0; i < length; i++) {
        E element = this[i];
        if (test(element)) return element;
        if (length != this.length) {
          throw new ConcurrentModificationError(this);
        }
      }
      if (orElse != null) return orElse();
      throw IterableElementError.noElement();
    }