如何检查node.js中的查询字符串中是否存在参数

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 the parameter is not present in your queryString it is returned as undefined . The parameter wouldn't return null because it wasn't initialised.

try this :

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