检测表单字段值是否已被修改

Question

I have a multi-step form which asks the subscriber to check their details before proceeding with the renewal process.

What I want to do is check if the form has been modified from its pre-filled values (extracted from a Web Service) and then write it to my own local MySQL database. This should only happen if the values have been modified from the original.

I know I can do this by using the == operator but I was wondering if there was a more efficient way to do this?

Answer 1

You can do it with (multidimensional) arrays. Name the form/service variables carefully then compare them upon submit with array_diff which tells you which values has been modified. Because you said this is a multi-step form, of course you can collect previously submitted values in a $_SESSION variable too.