C++ Substract the end of a string, not knowing length of the result -

i have string this: 001,"john marvin","doctor", "full time" want delete after (001) substr, but, length of (001) not 3 can not put thie:

string chain = "001,\"john marvin\",\"doctor\", \"full time\"";  

std::string partial = chain.substr(0,3);

how can proceed in case?

you find index of first comma , use determine cut off string.

something like:

string chain = "001,\"john marvin\",\"doctor\", \"full time\""; int cutoff = chain.find(','); string newstring = chain.substr(0, cutoff); 

tested here.