Learning JavaScript Data Structures and Algorithms - Third Edition

O(1)

Consider the following function:

function increment(num){ 
  return ++num; 
} 

If we try to execute the increment(1) function, we will have an execution time equal to x. If we try to execute the increment function again with a different parameter (let's say num is 2), the execution time will also be x. The parameter does not matter; the performance of the function increment will be the same. For this reason, we can say the preceding function has a complexity of O(1) (which is constant).