How to identify dynamic elements or Xpaths in Selenium

Many web sites create dynamic element on their web pages where Ids of the elements gets generated dynamically. Each time id gets generated differently. So to handle this situation we use some JavaScript functions.
starts-with
if your dynamic element's ids have the format  where button id="continue-12345"  where 12345 is a dynamic number you could use the following
XPath: //button[starts-with(@id, 'continue-')]
contains
Sometimes an element gets identfied by a value that could be surrounded by other text, then contains function can be used.
To demonstrate, the element  can be located based on the ‘suggest’ class without having to couple it with the ‘top’ and ‘business’ classes using the following
XPath: //input[contains(@class, 'suggest')].