best way to get a specific object from and array without looping

Question

In one of the controllers of my angular application i have a variable set as follows.

SomeService.get({}, function(data){
    // this sets xyz as the list of         


        

Answer 1

No, you can't really avoid looping (O(n)) unless there are some preconditions met.

• If the array is sorted by id, you can use a binary search algorithm (O(log n)).
• If the array index always corresponds to the id-1 (or some similar simple formula), you can directly access it in O(1).

If those conditions are not fulfilled initially, but you need to access the items by id multiple times, it could be helpful to bring them in that form (sorting/building a hash map).