Hello,

Can you please elaborate on the use-case ?

Are you referring to the "id" of the UI elements, such as <input> <div> etc ?

"Also if the unique id will change dynamically everytime time we open the application." which id is being referenced here ?

Yogesh,

It is quite possible for a web application to recycle element id's across multiple objects with the same type. I have seen this occur, but it is on rare occasion. 

Most issues of using element id are a result of the web application containing a pool of element ids to choose from, and dynamically assign those element ids to various objects within web application's page every time the page is reloaded.

When either of the above has occurred,  it is not recommended to use element id match rule as a method to identify such controls. However, there are very many instances in which the element id is static for the web controls and are safe to use. You will need to test thoroughly with your automation and Studio interrogation to see if that is the case.

Keep in mind, that the element id is the fastest match rule technique to use to identify control through matching. So if you are able to use this match rule successfully with a static element id assigned web control, it is best to do so.