The FindFirstGreaterThan function has a linear runtime complexity, often known as O(n), where n is the length of the input list.
This means that the time required to execute the function grows linearly in proportion to the size of the list. In the best-case situation, the first item in the list is greater than the stated value, and the function can return that value immediately rather than iterating through the rest of the list.
However, the best case and worst case scenarios are the same for this function because it iterates through the entire list in the worst case, checking each value against the specified value until a greater value is found or the end of the list is reached.