#include <iostream>
#include <cctype>     //字符函数原型头文件 
using namespace std;

int main()
{
  cout << "Enter text for analysis, and type # to terminate input.\n";

  char ch;  

  //统计变量初始化
  int whitespace = 0;
  int digits = 0;
  int chars = 0;
  int punct = 0;
  int others = 0;

  cin.get(ch);                // get first character 这样处理不会忽略空格、制表符、换行符

  while (ch != '#')            // test for sentinel
  {
    if(isalpha(ch))         // 字符
      chars++;
    else if(isspace(ch))    // 标准空白字符，如空格、进纸、换行符、回车、水平制表符或者垂直制表符
      whitespace++;
    else if(isdigit(ch))    // 数字(0~9)
      digits++;
    else if(ispunct(ch))    // 标点符号
      punct++;
    else
      others++;
    cin.get(ch);            // get next character
  }
  cout << chars << " letters, "
    << whitespace << " whitespace, "
    << digits << " digits, "
    << punct << " punctuations, "
    << others << " others.\n";
  return 0; 
}

cctype字符函数库使用_标准