How to handle collision detection (In terms of data structures)

Question

I am making a 2D game with SDL2. I made my Collider class, I assign colliders to my objects. Everything is okay, but I am wondering what way of handling collision check is more efficient. One way in my mind is making a global array that holds all colliders and every move the array will be checked by my main character iteratively. This has a O(n) complexity. Another way is making a hash table that is hashed with collider's positions. This way has a constant complexity but this way is too costly because of rehashing, I believe. What do you think about it? And do you know how unreal engine or other game engines handle collision checks?