Examples of time complexity

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.

Constant time

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. 

Logarithmic time

A Logarithmic time function is one in which the time of execution is proportional to the logarithm of the input size. Consider the following example:

for(var i = 1; i < N; i *= 2) {
    // O(1) operations...