Let's now examine some examples of time complexity calculations, since in 99% of the cases we need to know the maximum time a function might take to execute; we will be mostly analyzing the worst case time complexity, that is, the upper bound of the rate of growth based on the input of a function.
A constant time function is one which takes the same amount of time to execute, irrespective of the size of the input that is passed into the function:
function square(num) { return num*num; }
The preceding code snippet is an example of a constant time function and is denoted by O(1). Constant time algorithms are the most sought out algorithms for obvious reasons, such as them running in a constant time, irrespective of the size of the input.