Question

c# 计算一串字符中某个字母出现的次数

Answer 1

public int getcount(string chr,string str)/*chr：字符串中找的字符， str：字符串*/
{
int count=0;

for (int i = 0; i < str.Length; i++)
{
if (chr == str.Substring(i, 1))
count++;
}
return count;
}

Answer 2

string str="12a3a234";
int c=str.ToCharArray().Count(p => p == 'a');

Answer 3

写个函数，参数为该字母，把字符串分解到byte数组里，然后foreach遍历即可

Answer 4

string a = "weretertrtert";
int i = 0;
foreach (char b in a)
{
if (b ==Convert.ToChar("e"))
{
i++;
}
}
MessageBox.Show(i.ToString());

Answer 5

使用map实现