Answers for "what does vector.size() = 0 mean"

size of a matrix using vector c++

// finding size of a square matrix
myVector[0].size();

c++ vector size

#include <vector>

int main() {
  std::vector<int> myVector = { 666, 1337, 420 };
  
  size_t size = myVector.size(); // 3
  
  myVector.push_back(399); // Add 399 to the end of the vector
  
  size = myVector.size(); // 4
}