C++ 字符串操作常用函数

集合网上一些常用的字符串操作，全部验证可用

1.字符串替换（char*型）

#include <stdio.h>#include <stdlib.h>#include <ctype.h>#include <string.h>//字符串替换函数/******************************************************************** *  Function：  my_strstr() *  Description: 在一个字符串中查找一个子串; *  Input：      ps: 源;      pd：子串 *  Return :    0：源字符串中没有子串; 1：源字符串中有子串; *********************************************************************/char * my_strstr(char * ps, char *pd) {char *pt = pd;int c = 0;while (*ps != '\0') {if (*ps == *pd) {while (*ps == *pd && *pd != '\0') {ps++;pd++;c++;}} else {ps++;}if (*pd == '\0') {return (ps - c);}c = 0;pd = pt;}return 0;}/******************************************************************** *  Function：  memcpy() *  Description: 复制一个内存区域到另一个区域; *  Input：      src: 源; count: 复制字节数. *  Output：      dest: 复制目的地; *  Return :      dest; *********************************************************************/void * memcpy(void * dest, const void *src, size_t count) {char *tmp = (char *) dest, *s = (char *) src;while (count--)*tmp++ = *s++;return dest;}/******************************************************************** *  Function：  str_replace() *  Description: 在一个字符串中查找一个子串，并且把所有符合的子串用 另一个替换字符串替换。 *  Input：      p_source:要查找的母字符串； p_seach要查找的子字符串; p_repstr：替换的字符串; *  Output：      p_result:存放结果; *  Return :      返回替换成功的子串数量; *  Others:      p_result要足够大的空间存放结果，所以输入参数都要以\0结束; *********************************************************************/int str_replace(char *p_result, char* p_source, char* p_seach, char *p_repstr) {int c = 0;int repstr_leng = 0;int searchstr_leng = 0;char *p1;char *presult = p_result;char *psource = p_source;char *prep = p_repstr;char *pseach = p_seach;int nLen = 0;repstr_leng = strlen(prep);searchstr_leng = strlen(pseach);do {p1 = my_strstr(psource, p_seach);if (p1 == 0) {strcpy(presult, psource);return c;}c++;  //匹配子串计数加1;printf("结果:%s\r\n", p_result);printf("源字符:%s\r\n", p_source);// 拷贝上一个替换点和下一个替换点中间的字符串nLen = p1 - psource;memcpy(presult, psource, nLen);// 拷贝需要替换的字符串memcpy(presult + nLen, p_repstr, repstr_leng);psource = p1 + searchstr_leng;presult = presult + nLen + repstr_leng;} while (p1);return c;}#define MAX 200int main(void) {int i = 0;char s[MAX] = { 0 };        //存放源字串char s1[MAX] = { 0 };        //存放子字串char s2[MAX] = { 0 };        //存放替换字串char result_a[2000] = { 0 };        //存放替换结果;char *p, *ptm, *pr;puts("Please input the string for s:");scanf("%s", s);puts("Please input the string for s1:");scanf("%s", s1);puts("Please input the string for s2:");scanf("%s", s2);ptm = s;pr = result_a;i = str_replace(pr, ptm, s1, s2);printf("替换%d个子字符串;\r\n", i);printf("替换后结果:%s\r\n", result_a);system("pause");}

2.字符串替换（CString型）

CString str = L"AAABBBCCC";str.Replace(L"BBB", L"DDD");MessageBox(str);

3.字符串转换

wchar_t * ANSIToUnicode(const char* str){int textlen;wchar_t * result;textlen = MultiByteToWideChar(CP_ACP, 0, str, -1, NULL, 0);result = (wchar_t *)malloc((textlen + 1)*sizeof(wchar_t));memset(result, 0, (textlen + 1)*sizeof(wchar_t));MultiByteToWideChar(CP_ACP, 0, str, -1, (LPWSTR)result, textlen);return result;}char * UnicodeToANSI(const wchar_t* str){char* result;int textlen;textlen = WideCharToMultiByte(CP_ACP, 0, str, -1, NULL, 0, NULL, NULL);result = (char *)malloc((textlen + 1)*sizeof(char));memset(result, 0, sizeof(char) * (textlen + 1));WideCharToMultiByte(CP_ACP, 0, str, -1, result, textlen, NULL, NULL);return result;}wchar_t * UTF8ToUnicode(const char* str){int textlen;wchar_t * result;textlen = MultiByteToWideChar(CP_UTF8, 0, str, -1, NULL, 0);result = (wchar_t *)malloc((textlen + 1)*sizeof(wchar_t));memset(result, 0, (textlen + 1)*sizeof(wchar_t));MultiByteToWideChar(CP_UTF8, 0, str, -1, (LPWSTR)result, textlen);return result;}char * UnicodeToUTF8(const wchar_t* str){char* result;int textlen;textlen = WideCharToMultiByte(CP_UTF8, 0, str, -1, NULL, 0, NULL, NULL);result = (char *)malloc((textlen + 1)*sizeof(char));memset(result, 0, sizeof(char) * (textlen + 1));WideCharToMultiByte(CP_UTF8, 0, str, -1, result, textlen, NULL, NULL);return result;}char* ANSIToUTF8(const char* str){return UnicodeToUTF8(ANSIToUnicode(str));}char* UTF8ToANSI(const char* str){return UnicodeToANSI(UTF8ToUnicode(str));}

//UTF-8 GBK  int UTF82GBK(char *szUtf8, char *szGbk, int Len){int n = MultiByteToWideChar(CP_UTF8, 0, szUtf8, -1, NULL, 0);WCHAR * wszGBK = new WCHAR[sizeof(WCHAR) * n];memset(wszGBK, 0, sizeof(WCHAR) * n);MultiByteToWideChar(CP_UTF8, 0, szUtf8, -1, wszGBK, n);n = WideCharToMultiByte(CP_ACP, 0, wszGBK, -1, NULL, 0, NULL, NULL);if (n > Len){delete[]wszGBK;return -1;}WideCharToMultiByte(CP_ACP, 0, wszGBK, -1, szGbk, n, NULL, NULL);delete[]wszGBK;wszGBK = NULL;return 0;}

4.判断字符串是否有非法字符

BOOL IsOnlyCharacterOrNum(CString str)//是否纯字母或数字{for (int i = 0; i<str.GetLength(); i++){if (str.GetAt(i)<'0' || (str.GetAt(i)>'9' && str.GetAt(i)<'A') || (str.GetAt(i)>'Z' && str.GetAt(i)<'a') || str.GetAt(i)>'z')return FALSE;}return TRUE;}BOOL IsOnlyNum(CString str)//是否纯数字{for (int i = 0; i<str.GetLength(); i++){if (str.GetAt(i)<'0' || str.GetAt(i)>'9')return FALSE;}return TRUE;}

5.字符串分割

//分割字符串int SplitString(CString str, CString split, CStringArray &strArray)//分割符为字符串split,str为被分割的字符串{strArray.RemoveAll();CString strTemp = str;int iIndex = 0;while (1){iIndex = strTemp.Find(split);if (iIndex >= 0){strArray.Add(strTemp.Left(iIndex));strTemp = strTemp.Right(strTemp.GetLength() - iIndex - split.GetLength());}else{break;}}strArray.Add(strTemp);return strArray.GetSize();}

int SplitString(const char* str, char split, CStringArray &strArray)//分割符为字符split，被分割字符串为char*型{strArray.RemoveAll();CString strTemp(str);int iIndex = 0;while (1){iIndex = strTemp.Find(split);if (iIndex >= 0){strArray.Add(strTemp.Left(iIndex));strTemp = strTemp.Right(strTemp.GetLength() - iIndex - 1);}else{break;}}strArray.Add(strTemp);return strArray.GetSize();}