when we define the vector it has a huge max_size() but sir is saying that every time it has a push_back operation and memory double but we have to copy all the content of the previous container to newly allocated vector. so what is the need of coping content every time?
Regarding vector size
Your question is not clear please explain.
@gauravlodhi21 I will try to explain the concept.
See vector has a big reserve of memory, we can add the elements to vector till its size is less then the reserve memory as soon as the size of vector becomes equal to reserve memory we create a new vector with its reserve size twice the reserve size of old vector. Now we copy the content of old vector to new vector. We are copying contents only when our reserve capacity is reached and we are creating new vector, otherwise their is no need to copy.
If this resolves your doubt mark it as resolved.