Is there a way to reduce if else conditions while validating all the keys of a request payload?

I have a request payload with multiple keys (about 20 to 30) like name, email, phone number, address etc and some of these are optional.

To validate those I use multiple if/else conditions and in some cases I need to include validation based on a dependent key too.

For example: If I have a value in the address key, then values for the city, state and zip keys are mandatory. In this scenario I have a bunch of if/else conditions in my code. Is there a way to minimize the if conditions and improve my code?

I’m expecting to reduce the number of if/else conditions