Enumerable.Select(TSource, TResult) メソッド (IEnumerable(TSource), Func(TSource, Int32, TResult)) (System.Linq) public static IEnumerable<TResult> Select<TSource, TResult>( this IEnumerable<TSource> source, Func<TSource, int, TResult> selector ) 要素が 1 個でも 1000 個でも変わるのは 1 ms 程度だっ</tsource,></tsource></tsource,></tresult>…