STL MAP should use find() or [n] identifier to find element in map?

Question

I am confused which is more efficient?

As we can access map directly, why do we need to use find?

I just need to know which way is more efficient.

Answer 1

The [] operator in map is not constant it is logarithmic. Most of the books stress on this fact and point out it is a bit misleading. So both find and [] operator are with the same complexity.

Please note that the [] operator will create the entry even if it does not exist while find will return end() in that case.