Counting sheep...

Consider an array of sheep where some sheep may be missing from their place. We need a function that counts the number of sheep present in the array (true means present).

For example,

[true,  true,  true,  false,
  true,  true,  true,  true ,
  true,  false, true,  false,
  true,  false, false, true ,
  true,  true,  true,  true ,
  false, false, true,  true]

using System;

public static class Kata
{
  public static int CountSheeps(bool[] sheeps)
  {
    int count = 0;
    for(int i = 0; i < sheeps.Length; i++) {
      if (sheeps[i]) count++;
    }
    return count;
  }
}

比较好的方法，是使用Linq

using System;
using System.Linq;

public static class Kata
{
  public static int CountSheeps(bool[] sheeps)
  {
    return sheeps.Count(s => s);
  }
}

Array类的扩展方法Count

public static int Count<TSource>(this IEnumerable<TSource> source, Func<TSource, bool> predicate);