Don't install Node.js directly from `apt`—it's hideously out of date, and most of the features you're expecting to have **won't work**. The version in the repositories at the minute is [v0.10.29](https://packages.debian.org/jessie/nodejs), when the current release as of writing is v7.10.0.

Instead, follow the advice given to install Node (and npm) from [their website](https://nodejs.org/en/download/package-manager/#debian-and-ubuntu-based-linux-distributions):

    curl -sL https://deb.nodesource.com/setup_7.x | sudo -E bash -
    sudo apt-get install -y nodejs

Note that this will only work for Pis with an ARMv7 (or greater) processor—the Pi Zero and the original Model B won't cut it, as noted [here](http://thisdavej.com/beginners-guide-to-installing-node-js-on-a-raspberry-pi/).

After completing the installation, both Node.js and npm will be installed using the latest (or a very recent) version.