字符串中是否存在汉字，数字，英文

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int first(unsigned char ch)
{
 if(ch>=0xb0&&ch<=0xf7)
  return 1;
 else
  return 0;
}
int second(unsigned char ch)
{
 if(ch>=0xa1&&ch<=0xfe)
  return 1;
 else
  return 0;
}
int check(const char* p)
{
 int i=0;
 int len = strlen(p)-1;
 for(i=0;i<len;i++)
  if(first(p[i])&&second(p[i+1]))
   return 1;
 return 0;
}

bool ChooseChinese(const char *str,char *des)
{
 int i=0;
 int j = 0;
 bool ishave = false;
 int len = strlen(str)-1;
 for(i=0;i<len;i++)
 { 
  if(first(str[i])&&second(str[i+1]))
  {
   des[j] = str[i];
   j++;
   des[j] = str[i+1];
   j++;
   ishave = true;
  }
 }

 des[j] = '\0';
 return ishave;
}

bool ChooseDigit(const char *str,char *des)
{
 int i = 0;
 int j = 0;
 bool ishave = false;
 int len = strlen(str);
 for(i = 0;i<len;i++)
 {
  if(str[i]<='9'&&str[i]>='0')
  {
   ishave = true;
   des[j++] = str[i];
  }
 }
 des[j] = '\0';
 return ishave;
}
bool ChooseEnglish(const char *str,char *des)
{
 int i = 0;
 int j = 0;
 bool ishave = false;
 int len = strlen(str);
 for(i = 0;i<len;i++)
 {
  if((str[i]>='a'&&str[i]<='z')||(str[i]>='A'&&str[i]<='Z'))
  {
   ishave = true;
   des[j++] = str[i];
  }
 }
 des[j] = '\0';
 return ishave;
}
void main()
{
 const char* str= "sdfd中ds12123dfs年f好998998";
 char mystr1[100];
 char mystr2[100];
 char mystr3[100];
 check(str)?puts("there has character!"):puts("there has none character!");

 ChooseChinese(str,mystr1);
 printf("\nstring_chinese = %s\n",mystr1);

 ChooseDigit(str,mystr2);
 printf("\nstring_digit = %s\n",mystr2);

 ChooseEnglish(str,mystr3);
 printf("\nstring_English = %s\n",mystr3);
}

 

 

汉字是双字节的编码格式；

汉字的第一字节：是从0xB0   到0xF7   
汉字的第二字节：是从0xA1  到0xFE