title: Big O effeciency for multiple variables
body: <p>I'm trying to rate the efficiency of a function where the input is an array of strings.  The algorithm always iterates through every item in this array.  This strings contained in this array are of variable length.  In this initial for loop, a character replace function is called on each string.  I believe the replace function on its own would be O(n) where n is the length of the string.</p>
  
  <p>So I'm confused how to evaluate big o efficiency here.  If n is the size of the array, I know it will at least be O(n).  But with variable string lengths, how would you rate the overall efficiency with the string replacement?  Would you say n is the size of the array and use other variables to represent the different sizes of each string?</p>