Does node.js shell have commands like python type?

Question

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 08:50
Indeed. ```obj==='undefined'``` assumes that ```obj``` is a string with the value of ```undefined```. — DarthJDG, Jun 13 '13 at 08:55
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 09:07
also in python you should not be using `type`, you should be using `isinstance` — jamylak, Jun 13 '13 at 09:34

score 1 · Accepted Answer · answered Jun 13 '13 at 09:07

1

> 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 09:07

Ashwini Chaudhary

1 Answers1