C++：将一行读取为：'string string;int'

Question

I have started coding lately(school curriculuim) and ran into a little problem. I want to read a.txt file, the lines are like "firstname lastname;phonenumber".

ifstream file("names.txt");

    string line, fname, lname;
    int num;

    while (getline(file, line)) {
        istringstream iss(line);
        iss >> fname >> lname >> num;
    }

So the problem is that the lastname is lastname + ";" + phone number and I don't know how to separate them. Any help is appreciated:)

Edit: Thanks for the quick replies!

Answer 1

Two possible solutions:

1. One relatively simple way is to read fname like you do now, then use std::getline with ';' as the separator (instead of the default newline) to get lname . Then you could read into num .

2. Get fname like you do now. Then get lname;num into a second string. Find the semi-colon and create two sub-strings , one for lname and one for num . Then convert the string containing num into an integer (with the caveat mentioned in my comment to the OP).

Answer 2

You can pass ; as a separator to getline when extracting lname .

std::ifstream file("names.txt");

for (std::string line; getline(file, line);) {
    std::istringstream iss(line);
    std::string fname, lname;
    int num;
    iss >> fname;
    getline(iss, lname, ';');
    iss >> num;
}

Answer 3

You can use string.find to find the semicolon, and then use string.substr to split the string.