I am stuck on this stupid doubt and can’t understand which part have I understood wrong.
I am trying to fill an empty string and I thought of doing it using the subscipt [] operator but found that although loop runs perfectly but the final string is still empty with size zero. However push_back runs perfectly fine. I can use push_back but want to understand the reason for the first one. If anyone can clarify?
string r;
int i;
for(i = 0; i < 5; ++i)
{
r[i] = 'a';
}
cout << r.size(); //output: 0
cout << endl;
for(i = 0; i < 5; ++i)
{
r.push_back('a');
}
cout << r.size(); //output: 5
>Solution :
As simple as it is for std::vector, std::string doesn’t have bounds check when using subscript operator. When creating empty string, you have a collection of zero length, thus when you assign values by index, the values are assigned to memory out of the collection’s bounds