how to check if a parameter is present in the querystring in node.js

Question

How to validate if a parameter is exits in the querystring or not in the node.js ?

I am validating like this

if(prm1 == null)
return error

But actually in the console.log(prm1) says undefined..

How to validate this exactly ?

Answer 1

If param is not present in your queryString, it return undefined, not null because the car is not initialized. try this :

if(typeof prm1 != 'undefined')
    return "error";