how to count characters in string in cpp code example

Example 1: count a character in a string c++

count(str.begin(), str.end(), 'e')

Example 2: count number of char in a string c++

string str_V;
char chr
getline(cin, str_V);
for(i=0; i<=str.length; i++)
{
 	  if(str[i]==chr)
      {
        space++
       }
}