C++：如何读取带有换行符和逗号分隔的 csv 文件

Question

I'm aware that this question has been asked. But I couldn't find a solution for my case. I have a file as follow:

4 
apple,banana,cat,donkey

My desired output is this:

apple|banana|cat|donkey|

And my code:

ifstream infile;
infile.open("file1.txt");

int num;
string line;
infile >> num;
infile >> line;
size_t pos = 0;
vector<string>data;
string a;
while ((pos = line.find(",")) != string::npos){
   a = line.substr(0, pos);
   data.push_back(a);
   line.erase(0, pos + (",".length()));
}
for (auto x: data)
   cout << x << "|";

By finding comma, I managed to read first 3 items, but failed to read the last one (donkey). How can I detect the newline with a similar method, preferably without getline? It failed when I use newline as delimiter.

Answer 1

Add the condition after the loop

if (!line.empty())
  data.push_back(line);

This will add the tail after the last comma to the vector.

New line is not placed at the end of the line when you read a string from an input stream like ifile >> line; .