c++ string 與 char 互轉

很簡單如下

?

char bts[5] = {'A','B','C','D','E'};printf("%s\n",bts);//char to stringstd::string strBts = bts;std::cout << strBts << std::endl;//string to charchar *theBts = (char *)strBts.c_str();printf("%s\n",theBts);

?

c++ base64 工具

// // base64.h // CPPWork // from http://stackoverflow.com/questions/180947/base64-decode-snippet-in-c // Created by cocoa on 16/8/5. // Copyright ? 2016年 cc. All rights reserved. // #ifndef base64_h #define base64_h#include <string>std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len); std::string base64_decode(std::string const& encoded_string);#endif /* base64_h */ View Code

?

// // base64.cpp // CPPWork // // Created by cocoa on 16/8/5. // Copyright ? 2016年 cc. All rights reserved. // #include "base64.h" #include <iostream>static const std::string base64_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz" "0123456789+/";static inline bool is_base64(unsigned char c) {return (isalnum(c) || (c == '+') || (c == '/')); }std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {std::string ret;int i = 0;int j = 0;unsigned char char_array_3[3];unsigned char char_array_4[4];while (in_len--) {char_array_3[i++] = *(bytes_to_encode++);if (i == 3) {char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);char_array_4[3] = char_array_3[2] & 0x3f;for(i = 0; (i <4) ; i++)ret += base64_chars[char_array_4[i]];i = 0;}}if (i){for(j = i; j < 3; j++)char_array_3[j] = '\0';char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);char_array_4[3] = char_array_3[2] & 0x3f;for (j = 0; (j < i + 1); j++)ret += base64_chars[char_array_4[j]];while((i++ < 3))ret += '=';}return ret;} std::string base64_decode(std::string const& encoded_string) {int in_len = encoded_string.size();int i = 0;int j = 0;int in_ = 0;unsigned char char_array_4[4], char_array_3[3];std::string ret;while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {char_array_4[i++] = encoded_string[in_]; in_++;if (i ==4) {for (i = 0; i <4; i++)char_array_4[i] = base64_chars.find(char_array_4[i]);char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];for (i = 0; (i < 3); i++)ret += char_array_3[i];i = 0;}}if (i) {for (j = i; j <4; j++)char_array_4[j] = 0;for (j = 0; j <4; j++)char_array_4[j] = base64_chars.find(char_array_4[j]);char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];for (j = 0; (j < i - 1); j++) ret += char_array_3[j];}return ret; } View Code

?

轉載于:https://www.cnblogs.com/cocoajin/p/5749266.html

總結

以上是生活随笔為你收集整理的c++ string 与 char 互转 以及base64的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。