Question

c# 如何判断字符串中相同字符串的个数

例如abcdefababctr........
怎么判断字符串中字符串"abc"的个数

Answer 1

这个，还是比较方便的，利用定长改变的逻辑就可以了，效率也非常高。
写成了一个函数，便于调用
------------------------------------------
/// <summary>
/// 计算字符串中子串出现的次数
/// </summary>
/// <param name="str">字符串</param>
/// <param name="substring">子串</param>
/// <returns>出现的次数</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;
}

使用的方法：
--------------------------------------
string a = "abcdefababctr";
string b = "abc";

int c = SubstringCount(a, b); //这里的c就是b在a中出现的次数了

Answer 2

using System;
using System.Collections.Generic;
using System.Text;

namespace BuggyApp
{
class Program
{
static void Main(string[] args)
{
int count = 0;
int index=0;
string a = "babcdlsjfabcldsjfabcljkbc";
foreach (char s in a)
{
if (s.Equals('b'))
{
if (index < a.Length && index > 0)
{
if (a[index - 1].Equals('a') && a[index + 1].Equals('c'))
{
count++;
}
}
}
index++;
}
Console.WriteLine(count.ToString());

}
}
}

Answer 3

请参照以下代码：

private void button1_Click(object sender, EventArgs e)
{
string origeString = "aaabcdfererabcdfdfabcdfer";
GetAppearenceCount(origeString, "abc");
}

private int GetAppearenceCount(string origeString, string objectString)
{
int count = 0;

int objectStringLength = objectString.Trim().Length;

for (int i = 0; i < origeString.Length; i++)
{

int indexExists = origeString.IndexOf(objectString);

if (indexExists < 0)
break;
else
{
origeString = origeString.Trim().Substring(indexExists + objectStringLength, origeString.Trim().Length - indexExists - objectStringLength);
count++;
}

}

return count;
}