How to delete an element from a vector while looping over it?

Question

I am looping through a vector with a loop such as for(int i = 0; i < vec.size(); i++). Within this loop, I check a condition on the element at that vector i

Answer 1

if(vector_name.empty() == false) {
    for(int i = vector_name.size() - 1; i >= 0; i--)
    {
        if(condition) 
            vector_name.erase(vector_name.at(i));
    }
}

This works for me. And Don't need to think about indexes have already erased.