Find function in cpp

#1

what if the substring whose index needs to be searched doesn’t exist in the string… so find function return error or -1… in that case…

#2

It will not give an error. It will return string::npos.
What is npos? You can refer this
https://www.educative.io/edpresso/what-is-stringnpos-in-cpp#:~:text=npos%20is%20a%20constant%20static,with%20a%20value%20of%20-1.

Also go through this article