Linq的TakeWhile的用法

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Can you find the needle in the haystack?

Write a function ​​findNeedle()​​ that takes an ​​array​​ full of junk but containing one ​​'needle'​​

After your function finds the needle it should return a message (as a string) that says:

​​'found the needle at position '​​ plus the ​​index​​ it found the needle

So

findNeedle(['hay', 'junk', 'hay', 'hay', 'moreJunk', 'needle', 'randomJunk'])

should return

'found the needle at position 5'

 

public static string FindNeedle(object[] haystack)
        {
            const string needle = "needle";
            var strings = haystack.Select(x => x.ToString());
            int position = strings.TakeWhile(str => !str.Equals(needle)).Count();
            return $"found the needle at position {position}";
        }