读取.csv文件并将值存储到vector和struct c ++中

Question

I am new to programming in C++ and am trying to do a practice problem, but I don't really understand what it is trying to get me to do since a vector can only hold one data type (unless it can hold more):

Read in a .csv file where each line is structured as such: "username,gpa,age". Store these values into a struct with username, gpa, and age (string,float,int) and create a list as a vector. As you read in each line, insert into the vector list sorted by username. Then loop through and print out the list formatted as : "username [gpa] age:#" eg, "mark [3.9] age:19" and also write the output to a file (using C++, not Unix).

Am I supposed to put all of those values into the same vector as separate data types or keep them all together in a string and then insert them? How do I store these values into a struct? If someone can tell me how they would solve the question and give me some sample code that'd be great, thank you.

Answer 1

Ok, by the sound of it, the question wants you to read the file, put the information into a struct, then insert the structs into the vector in alphabetical order according to the name.

I'd make the struct something like:

struct StudentInfo {
    string name;
    string gpa;
    string age;
} StudentInfo;

I'd then open the file and read the whole thing into a string. Then I'd read through the string, tokenizing it by newline character. As I get each string, I'd put it into a function that parsed it and returned a struct studentInfo. then insert the struct into the vector.

An example of how the parsing function might work:

struct StudentInfo parseData(string iStr) {
    struct StudentInfo info;
    size_t subStrStart = 0;
    size_t subStrEnd = 0;
    subStrEnd = iStr.find(',', subStrEnd);
    info.name = iStr.substr(subStrStart, subStrStart - subStrEnd);

    subStrStart = subStrEnd;
    subStrEnd = iStr.find(',', subStrEnd+1);
    info.gpa = iStr.substr(subStrStart, subStrStart - subStrEnd);

    subStrStart = subStrEnd;
    subStrEnd = iStr.find(',', subStrEnd+1);
    info.age = iStr.substr(subStrStart, subStrStart - subStrEnd);

    return info;
}

Some pseudocode for the main function I'd make:

vector<struct StudentInfo> infoVec;
string fileStr = read(filename.csv); // make an ifstream or something similar
string lineStr;
size_t subStrEnd = 0;
size_t subStrStart = 0;
while (subStrEnd < fileStr.Size) {
    subStrEnd = iStr.find('\n', subStrEnd); //alternatively use std::getline() directly on the file stream
    lineStr = iStr.substr(subStrStart, subStrStart - subStrEnd);
    subStrStart = subStrEnd;
    subStrEnd++;
    infoVec.insert(parseData(lineString));
}
sortByName(infoVec) // User defined function
printInfoVec(infoVec) // User defined function

The print function and the sort function are pretty self explanatory, they'd require you to write them though.