For example, if we have: John can save it in CSV file containing: These files are used to store tabular data. What is CSV and where’s the catch?ĬSV stands for comma-separated values. Surprisingly, I couldn’t find any premade code in Google and had to write it on my own. You can then iterate over the lines and parse them into variables and do whatever you need with them.Some time ago I needed a simple solution in pure C# for reading and writing CSV files.
This call will parse the raw data into a vector containing lines of Push back the final element in str when str contains no more delimiters Pos += str.substr(pos).find(delimiter) + delimiter.size() Move the pos past this found section and the found delimiter so the search can continue Ret.push_back(str.substr(pos, str.substr(pos).find(delimiter)))
Insert the substring from pos to the start of the found delimiter to the vector While(str.substr(pos).find(delimiter) != string::npos) While the the string from point pos contains the delimiter Vector dstov(string& str, string delimiter) You could then do something like this to parse your string: //Delimited string to vector This will be much faster than multiple read calls. You can load in the entire contents of the file using a single read call by knowing the size of the file using some fseek magic. I don't know if this will be quicker than the accepted answer, but I might as well post it anyway in case you wish to try it. Is there a faster approach using the standard library, or should I just use stdio functions? It seems to me this entire code block would reduce to a single fscanf call. The problem is, this is extremely slow (there are over 1 million rows per data file), and seems to me to be a bit inelegant. As such I've tried to stay the C++ way using the standard library, and my implementation within a loop looks something like: string field I am storing each column of this data into a STL vector.
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