• Returns the only element of a sequence, or a default value if the sequence is empty; this method throws an exception if there is more than one element in the sequence.

    Type Parameters

    • TSource

    Parameters

    • src: Iterable<TSource>

      An Iterable to return a single element from.

    • Optionalpredicate: (item: TSource, index: number) => boolean

      A function to test an element for a condition.

    Returns TSource | null

    The single element of the input sequence that satisfies a condition.

    TSource The type of the elements of source.