如何通过读取文件将不同数据类型的数据推入向量？
我想使用下面的代码将下面的数据推送到一个向量。但我的代码只适用于整数。我如何为以下数据执行此操作？ 谢谢。
我的数据：
M,0.455,0.365,0.095,0.514,0.2245,0.101,0.15,15 M,0.35,0.265,0.09,0.2255,0.0995,0.0485,0.07,7 F,0.53,0.42,0.135,0.677,0.2565,0.1415,0.21,9 M,0.44,0.365,0.125,0.516,0.2155,0.114,0.155,10 I,0.33,0.255,0.08,0.205,0.0895,0.0395,0.055,7 I,0.425,0.3,0.095,0.3515,0.141,0.0775,0.12,8 F,0.53,0.415,0.15,0.7775,0.237,0.1415,0.33,20 F,0.545,0.425,0.125,0.768,0.294,0.1495,0.26,16 M,0.475,0.37,0.125,0.5095,0.2165,0.1125,0.165,9 F,0.55,0.44,0.15,0.8945,0.3145,0.151,0.32,19 我的代码：
fp = fopen(argv[1], "r"); //Opening the input file in read mode. if(!fp) { printf("open data source file failed!\n"); goto MAINEXIT; } int ivalue; //extract data from files while(fscanf(fp,"%d,",&ivalue)!=EOF) { printf("Counter-%d\n",counter++); srcdata.push_back(ivalue); //Pushing value by value into the vector with "," delimiter. } if(fp) fclose(fp);
%d表示整数。 将其更改为%lf为double ，并相应地更改其他部分，例如，将ivalue更改为double 。
根据你在问题中的评论，我认为你可能需要类似的东西
while（fscanf（fp，“％s”，str）！= EOF）
{
char * pch = strtok（str，“，”）;
pch = strtok（NULL，“，”）; //先跳过
while（pch！= NULL）
{
double d = atof（pch）;
的printf（ “反％d \ n” 个，计数器++）;
srcdata.push_back（d）;
pch = strtok（NULL，“，”）;
}
}
由于您使用的是C ++ STL容器（ vector ），因此您应该使用C ++ I / O（ iostream ）而不是CI / O（ stdio ）。 它更安全，更灵活，最终可以为您节省一些胃灼热。
这是一个快速的脏样本，展示了如何将数据读入矢量：
#include #include #include #include #include #include /** * Create a struct type to represent each record, * with one char member (which I'm calling "gender" * based on the 'M' and 'F', but that's just a guess), * 7 doubles (which I've gathered into a fixed-size * array), and one integer. * * I've also overloaded the stream << and >> operators * to read and write the struct as a single entity. */ struct record { char gender; double dvar[7]; int ivar; record() { } virtual ~record() { } std::ostream& operator<<(std::ostream& s) { s << gender << " "; for (int i = 0; i < 7; i++) s << std::fixed << std::setw(8) << std::setprecision(4) << dvar[i] << " "; s << std::setw(3) << ivar; return s; } std::istream& operator>>(std::istream& s) { char delim; s >> gender >> delim; for (int i = 0; i < 7; i++) s >> dvar[i] >> delim; s >> ivar; return s; } }; /** * Overload the << and >> operators outside of the struct * definition; this is necessary for the istream and ostream * iterators to function properly. Each operator simply * calls the overloaded operator in the struct definition */ std::ostream& operator<<(std::ostream& s, const record& r) { const_cast(r).operator<<(s); return s; } std::istream& operator>>(std::istream& s, record& r) { r.operator>>(s); return s; } /** * For the purpose of this example I'm reading from a string * stream local to main; however, you can swap out the string * stream with a C++ file stream (ifstream) and use it in the * copy method *exactly* as you use the string stream: * * std::ifstream infile(filename); * ... * std::copy(std::istream_iterator(infile), * std::istream_iterator (), * std::back_inserter(myRec)); */ int main(void) { std::vector myRec; /** * We're using a local string and string stream for the purpose of * this example, but the handling of a string stream and a file * stream would be exactly the same. */ std::string data = "M,0.455,0.365,0.095,0.514,0.2245,0.101,0.15,15" "M,0.35,0.265,0.09,0.2255,0.0995,0.0485,0.07,7" "F,0.53,0.42,0.135,0.677,0.2565,0.1415,0.21,9" "M,0.44,0.365,0.125,0.516,0.2155,0.114,0.155,10" "I,0.33,0.255,0.08,0.205,0.0895,0.0395,0.055,7" "I,0.425,0.3,0.095,0.3515,0.141,0.0775,0.12,8" "F,0.53,0.415,0.15,0.7775,0.237,0.1415,0.33,20" "F,0.545,0.425,0.125,0.768,0.294,0.1495,0.26,16" "M,0.475,0.37,0.125,0.5095,0.2165,0.1125,0.165,9" "F,0.55,0.44,0.15,0.8945,0.3145,0.151,0.32,19"; std::stringstream dataStream; /** * Write the contents of the string to the string stream */ dataStream << data; /** * Read the contents of the string stream into the vector */ std::copy(std::istream_iterator (dataStream), std::istream_iterator (), std::back_inserter(myRec)); std::cout << "Read " << myRec.size() << " records" << std::endl; /** * Write the contents of the vector to standard output. */ std::copy(myRec.begin(), myRec.end(), std::ostream_iterator (std::cout, "\n")); return 0; }
这非常简单; 没有任何error handling或处理格式错误的输入的方法。 但是，我认为它很好地说明了C ++ I / O例程的强大function。
但是，如果您遇到CI / O，则可以执行以下操作：
struct record { char gender; double dvar[7]; int ivar; }; int getRecord(FILE *stream, struct record *r) { char line[80]; // assuming each line is less than 80 characters long if (fgets(line, sizeof line, stream)) { int count = sscanf(line, "%c,%f,%f,%f,%f,%f,%f,%f,%d", &r->gender, &r->dvar[0], &r->dvar[1], &r->dvar[2], &r->dvar[3], &r->dvar[4], &r->dvar[5], &r->dvar[6], &r->ivar); if (count < 8) { fprintf(stderr, "Input line \"%s\" is malformed\n", line); return 0; } } else { if (feof(stream)) { fprintf(stderr, "Reached end of file\n"); } else { perror("Error on read"); } return 0; } return 1; } int main(void) { std::vector myRec; FILE *input = fopen("myfile.dat", "r"); record r; while(getRecord(input, &r)) myRec.push_back(r); ... }
我强烈建议使用C ++ I / O例程; 将CI / O与C ++混合是胃灼热的一种方法。