Does node.js shell have commands like python type? [duplicate]

Question

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I want to know whether a object is null or undefined so I use the following code:

if(obj==='undefined'||obj===null)

But it doesn't seem to work. Is there similar python type command to get the type of obj in node.js shell? Thanks!

I guess you're looking for typeof: typeof(foo) --> "undefined" — Ashwini Chaudhary, Jun 13 '13 at 8:50
Indeed. obj==='undefined' assumes that obj is a string with the value of undefined. — DarthJDG, Jun 13 '13 at 8:55
Underscore.js has some handy functions to check for variable types (isNull and isUndefined in your case), but nothing can substitute learning Javascript of course :). — kapa, Jun 13 '13 at 9:07
also in python you should not be using type, you should be using isinstance — jamylak, Jun 13 '13 at 9:34

Ashwini Chaudhary · Accepted Answer · 2013-06-13 09:07:36Z

up vote 1 down vote accepted

> typeof foo == 'undefined'
true
> typeof 1 == 'number'
true

This should work for you:

if( typeof obj === 'undefined' || obj === null)

From docs:

The typeof operator returns a string indicating the type of the unevaluated operand.

answered Jun 13 '13 at 9:07

Ashwini Chaudhary
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marked as duplicate by kapa, jamylak, TerryA, Joe, David M Jun 13 '13 at 10:45