How to enter an indefinite number of lines in C++?

Question

C++ / C#

Hello. I’ll make a reservation right away, I just started studying strings, I don’t know vectors and much more ... You need to enter an indefinite number of strings. The problem is that I don't know how to do it. My knowledge is clearly not enough for this. Please, help.

Answer 1

Such a condition means that you need to work with the string character by character, and not write it all into memory, because there may not be enough memory.

Answer 2

Write the problem in full, because it is not clear what you need, but as an option to solve such tasks through a buffer. Conventionally, you copy a 50GB file, but instead of reading 50GB into memory, you read 1MB and remember the position until the copy is over.

Answer 3

If this is an arbitrary length in the sense of not "you need to count exactly 5 characters", then you can read in std::string. It will allocate enough memory on its own.
This is how one word is read until a space (or end of file):

std::string s;
std::cin >> s;

This is how the whole line is read until the line break (or the end of the file): Then you can go through string as if it were an array, from 0 to s.length()-1.
std::getline(cin, s);