AnyAndAll

static class Extensions {

    /// <summary>
    /// Determines whether a sequence contains any elements and whether all elements of a sequence satisfy a condition.
    /// </summary>
    /// <typeparam name="T">The type of the elements of source.</typeparam>
    /// <param name="source">An IEnumerable<T> that contains the elements to apply the predicate to.</param>
    /// <param name="predicate">A function to test each element for a condition.</param>
    /// <returns>true if every element of the source sequence passes the test in the specified predicate and the sequence is not empty; otherwise, false.</returns>
    public static bool AnyAndAll<T>(this IEnumerable<T> source, Func<T, bool> predicate) {
        bool result = false;
        foreach (T item in source) {
            result = true;
            if (!predicate(item)) {
                result = false;
                break;
            }
        }
        return result;
    }
}

int[] a = new [] {1, 2, 3};
int[] e = Array.Empty<int>();

Console.WriteLine(a.AnyAndAll(n => n > 0)); // True, not empty and all above 0
Console.WriteLine(a.AnyAndAll(n => n > 1)); // False, not empty and first value is not above 0
Console.WriteLine(e.AnyAndAll(n => n > 0)); // False, e is Empty

Console.WriteLine();

Console.WriteLine(a.All(n => n > 0)); // True, all above 0
Console.WriteLine(a.All(n => n > 1)); // False, first value is not above 0
Console.WriteLine(e.All(n => n > 0)); // True, e is Empty