C#統(tǒng)計字符串中某字符串出現(xiàn)次數(shù)示例

NaturalWill 2014-04-25

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在C#中要統(tǒng)計一個字符出現(xiàn)在字符串中的次數(shù)我們有N種實現(xiàn)方法，下面我總結(jié)了幾種統(tǒng)計字符串出現(xiàn)資次數(shù)實例與大家分享。

例1

代碼如下

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計算一個字符串中的某個子串出現(xiàn)的次數(shù)，有沒有好的方法？
/// <summary>
/// 計算字符串中子串出現(xiàn)的次數(shù)
/// </summary>
/// <param name=”str”>字符串</param>
/// <param name=”substring”>子串</param>
/// <returns>出現(xiàn)的次數(shù)</returns>
static int SubstringCount(string str, string substring)
{
if (str.Contains(substring))
{
string strReplaced = str.Replace(substring, “”);
return (str.Length – strReplaced.Length) / substring.Length;
}

return 0;
}
int count = SubstringCount(“ddddfdfhgfjghjhgjghjhjhjhjhj”, “gh”);

例2 哈希表

代碼如下

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Hashtable ht = new Hashtable();
                string sr = "aaabbcddddd";
                char[] cr = sr.ToCharArray();
                foreach (char ch in cr)
                {
                    if (ht.ContainsKey(ch))
                    {
                        int i = (int)ht[ch];
                        ht.Remove(ch);
                        ht.Add(ch, ++i);
                    }
                    else
                        ht.Add(ch, 1);
                }
                foreach (DictionaryEntry dicEntry in ht)
                {
                    Console.WriteLine("{0}出現(xiàn){1}次", dicEntry.Key, dicEntry.Value);
                }
                ArrayList alist = new ArrayList(ht.Values);
                alist.Sort();
                object o = (object)alist[alist.Count - 1];
                foreach (DictionaryEntry dicEntry in ht)
                {
                    if (dicEntry.Value == o)
                    {
                        string str = dicEntry.Key.ToString();
                        Console.WriteLine("出現(xiàn)次數(shù)最多的字符:{0}，共{1}次", str, o.ToString());
                        break;
                    }
                }
                Console.ReadLine();

例3 linq

代碼如下

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string s = "aaabccccef";
            char[] c = s.ToCharArray();
            var cc = c.GroupBy(e => e).OrderByDescending(e => e.Count()).ToList();
            for (int i = 0; i < cc.Count; i++)
            {
                Console.WriteLine("{0}t{1}", cc[i].Key.ToString(), cc[i].Count().ToString());
            }
            var ccc = c.GroupBy(e => e).OrderByDescending(e => e.Count()).First().ToList();

            Console.WriteLine("{0}出現(xiàn){1}次！", ccc[0].ToString(), ccc.Count().ToString());
            Console.ReadKey();

例1

代碼如下

復(fù)制代碼