isset() use techniques in php 


isset() is the most commonly used php construct as well as a good friend of  a programmer. we frequently use it to check whether a variable has been set or not. it returns true if the variable has been set otherwise false… also return false if the variable has been set to null.

isset() is the only one of the three language constructs that accepts an arbitrary amount of parameters. Its accurate prototype is as follows:

isset($var1, $var2, $var3, …);
It only returns true, if all the variables have been defined; otherwise, it returns false. This is useful when you want to check if the required input variables for your script have really been sent by the client, saving you a series of single isset() checks.

So writing it with arbitrary parameters can be interesting upon your need! cheers!