If you're referring to the shell command line, either of the following will work:

node -v

node --version

Just typing node version will cause node.js to attempt loading a module named version, which doesn't exist unless you like working with confusing module names.

Try nodejs instead of just node

$ nodejs -v
v0.10.25

If you want to check in command prompt use node -v or node --version

v6.9.5

If u have node.exe then in node you can give.

>process
process {
  title: 'node',
  version: 'v6.9.5',
  .......

Just type npm version in your command line and it will display all the version details about node, npm, v8 engine etc.

Repl Command to find the Nodejs Version

$node
>process.version
`v8.x`

Node:

node --version or node -v

npm:

npm --version or npm -v

V8 engine version:

node -p process.versions.v8

find the installed node version.

$ node --version

or

 $ node -v

And if you want more information about installed node(i.e. node version,v8 version,platform,env variables info etc.)

then just do this.

$ node
> process
  process {
  title: 'node',
  version: 'v6.6.0',
  moduleLoadList: 
   [ 'Binding contextify',
     'Binding natives',
     'NativeModule events',
     'NativeModule util',
     'Binding uv',
     'NativeModule buffer',
     'Binding buffer',
     'Binding util',
     ...

where The process object is a global that provides information about, and control over, the current Node.js process.

Write this command to check the version of node.js

node --version

By default node package is nodejs, so use

$ nodejs -v

or

$ nodejs --version 

You can make a link using

$ sudo ln -s /usr/bin/nodejs /usr/bin/node

then u can use

$ node --version

or

$ node -v

One cool tip if you are using the Atom editor.

$ apm -v
apm  1.12.5
npm  3.10.5
node 4.4.5
python 2.7.12
git 2.7.4

It will return you not only the node version but also few other things.

For Node Js version -

node -v

Or

node --version

For NPM version -

npm -v

or

npm -version

in windows os we can't use nodejs -v, it doesn't work.

On an Arm7 (armhf) device running Debian Stretch, I had to issue either of the following:

$ nodejs -v
$ nodejs -h

The following did not work:

$ node -v
$ node -h
$ apm -v

Hope this helps someone else.

1. Open Command line prompt
2. node -v