C / C++ 读写文件方法

C 读写文件：
              File *fp;
              fp = fopen(const char* filename, const char* mode);  //mode = "r" "w"  "a" "r+"  "w+"
              int fputc(int a, fp);  //put a char to fp, and return the value of a
              char c = fgetc(fp);  //
              int fseek(fp, int offset, int whence);
              fputs(char *, fp);
              fgets(str, int size, fp);
              fprintf(fp, fmt, arguments);
              fscanf(fp, fmt, &arguments);

               fread(void *ptr, size_t size, size_t n, fp);
               fwrite(const void* ptr, size_t size, n, fp);             
 
C++读写文件：
           读：ifstream if("a.txt");
                  或者
                  ifstream if;
                  if.open("a.txt");
 
                  if>>variable; //空格作为结束符
                  if.getline(string line);
                  getline(if,string line );

           写：ofstream if("a.txt");
                  或者
                  ofstream if;
                  of.open("a.txt");
 
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