Is there another way to check if an array is empty

Question

I've added a condition that checks if an array is empty and automatically set an integer to larger than the size of the array since it's empty, but i get an "Index was outside the bounds of the array." mesage instead

    public static bool hurdleJump(int[] hurdles, int jumpHeight)
    {
        int max = hurdles[0];

        if (hurdles == null && hurdles.Length == 0)
        {
            return false;
        }
        else if (hurdles != null || hurdles.Length >= 1)
        {
            for (int i = 0; i < hurdles.Length - 1; i++)
            {
                max = max < hurdles[i+1] ? hurdles[i+1] : max;
            }
            if (jumpHeight >= max)
            {
                return true;
            }
        }
            return false;
    }

    static void Main(string[] args)
    {
        Console.WriteLine(hurdleJump(new int[] {}, 7));
    }

Does this answer your question? [What is an IndexOutOfRangeException / ArgumentOutOfRangeException and how do I fix it?](https://stackoverflow.com/questions/20940979/what-is-an-indexoutofrangeexception-argumentoutofrangeexception-and-how-do-i-f) — sticky bit, Jul 29 '20 at 10:57
`if (hurdles == null && hurdles.Length == 0)` should be `if (hurdles == null || hurdles.Length == 0)` Currently, you'll get a `NullReferenceException` if `hurdles` is null. Then you won't need the check against null in the `else if` condition. — Matthew Watson, Jul 29 '20 at 10:57
Also, you need to move the `int max = hurdles[0]` into the `else if` body. Have a think about why this is necessary. — Matthew Watson, Jul 29 '20 at 10:59
you also could use the Any() method, https://learn.microsoft.com/en-us/dotnet/api/system.linq.enumerable.any?view=netcore-3.1 — pbachman, Jul 29 '20 at 10:59
`hurdels[0]` accesses the **first** element, while you provide an **empty** one. Simply omit that line. — MakePeaceGreatAgain, Jul 29 '20 at 11:02

Andrew Arthur · Answer 1 · 2020-07-29T13:36:56.007

1

Moved the max initialization to after we've ensured handles is not null or empty.

Changed the first && to an ||.

 public static bool hurdleJump(int[] hurdles, int jumpHeight)
 {
     if (hurdles == null || hurdles.Length == 0)
     {
         return false;
     }
     else
     {
         int max = hurdles[0];
         for (int i = 0; i < hurdles.Length - 1; i++)
         {
             max = max < hurdles[i + 1] ? hurdles[i + 1] : max;
         }
         if (jumpHeight >= max)
         {
             return true;
         }
     }
     return false;
 }

edited Jul 29 '20 at 13:36

answered Jul 29 '20 at 11:09

Andrew Arthur

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In the "else" you don't need to re-check the condition of the "if". You already know it isn't true – Hans Keﬆing Jul 29 '20 at 12:33

Is there another way to check if an array is empty

1 Answers1