Try using n. After installing node in any way, eg. as described below:

curl -sL https://deb.nodesource.com/setup_12.x | sudo -E bash -
sudo apt-get install -y nodejs

you should have npm available. Install n with:

npm install -g n

and select correct version

• n lsr to list available versions
• n latest to use latest
• n 12.0.0 to use 12.0

Follow the directions on the "Installing Node.js via package manager" wiki page, section "Ubuntu, Mint, elementary OS", under "Obtaining a recent version of Node...", copied here:

sudo add-apt-repository ppa:chris-lea/node.js
sudo apt-get update
sudo apt-get install python-software-properties python g++ make nodejs

However, nodejs-legacy does not install for me either:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following NEW packages will be installed:
  nodejs-legacy
0 upgraded, 1 newly installed, 0 to remove and 6 not upgraded.
Need to get 15.4 kB of archives.
After this operation, 119 kB of additional disk space will be used.
Get:1 http://us-west-2.ec2.archive.ubuntu.com/ubuntu/ saucy/universe nodejs-legacy all 0.10.15~dfsg1-4 [15.4 kB]
Fetched 15.4 kB in 0s (243 kB/s)   
Selecting previously unselected package nodejs-legacy.
(Reading database ... 63176 files and directories currently installed.)
Unpacking nodejs-legacy (from .../nodejs-legacy_0.10.15~dfsg1-4_all.deb) ...
dpkg: error processing /var/cache/apt/archives/nodejs-legacy_0.10.15~dfsg1-4_all.deb (--unpack):
 trying to overwrite '/usr/share/man/man1/node.1.gz', which is also in package nodejs 0.10.26-1chl1~saucy1
Processing triggers for man-db ...
Errors were encountered while processing:
 /var/cache/apt/archives/nodejs-legacy_0.10.15~dfsg1-4_all.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

Node is one of the easier projects to build. Just change the version as that continues to change.

Browse to http://nodejs.org/dist/latest/ to find out the latest package version.

cd /usr/local/src
wget http://nodejs.org/dist/latest/node-v7.2.1.tar.gz
tar -xvzf node-v7.2.1.tar.gz
cd node-v7.2.1
./configure
make
sudo make install
which node

You should see /usr/local/bin/node.

NVM (Node Version manager)

https://github.com/nvm-sh/nvm

Advantages:

• allows you to use multiple versions of Node and without sudo

• is analogous to Ruby RVM and Python Virtualenv, widely considered best practice in Ruby and Python communities

• downloads a pre-compiled binary where possible, and if not it downloads the source and compiles one for you

Tested in Ubuntu 17.10:

curl https://raw.githubusercontent.com/creationix/nvm/master/install.sh | bash
source ~/.nvm/nvm.sh
nvm install 0.9.0
nvm install 0.9.9
nvm use 0.9.0
node --version
#v0.9.0
nvm use 0.9.9
node --version
#v0.9.9

For the particular case of the most recent long term support version (recommended if you can choose):

nvm install --lts
nvm use --lts
npm --version
npm install --global vaca
vaca

Since the sourcing has to be done for every new shell, the install script hacks adds some auto sourcing to the end of your .barshrc. That works, but I prefer to remove the auto-added one and add my own:

f="$HOME/.nvm/nvm.sh"
if [ -r "$f" ]; then
  . "$f" &>'/dev/null'
  nvm use --lts &>'/dev/null'
fi

With this setup, you get for example:

which node

gives:

/home/ciro/.nvm/versions/node/v0.9.0/bin/node

and:

which vaca

gives:

/home/ciro/.nvm/versions/node/v0.9.0/bin/vaca

and if we want to use the globally installed module:

npm link vaca
node -e 'console.log(require.resolve("vaca"))'

gives:

/home/ciro/.nvm/versions/node/v0.9.0/lib/node_modules/vaca/index.js

as mentioned at:

• NodeJS require a global module/package
• How do I import global modules in Node? I get "Error: Cannot find module <module>"?

so we see that everything is completely contained inside the specific node version.

For projects however, you are better off just using packages installed locally under node_modules and npx for executable to be able to have independent versions across projects, global usage is mostly for the Node executable itself and global CLI utilities not specific to any project.

Setting the NPM version

Simply:

npm install [email protected] -g

The executable is placed inside the current NVM version, so everything remains nice and isolated, e.g.:

which npm

gives something like:

/home/ciro/.nvm/versions/node/v14.17.0/bin/npm

How can I change the version of npm using nvm?

NodeSource provides binary distributions of Node.js; complete installation instructions can be found here. The instructions have been copied below for your reference. Instructions are the same for updating to the latest version.

Run once:

sudo apt-get update
sudo apt-get install -y ca-certificates curl gnupg
sudo mkdir -p /etc/apt/keyrings
curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key | sudo gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg

Run whenever you want to change the major version of Node.js:

NODE_MAJOR=20
echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] https://deb.nodesource.com/node_$NODE_MAJOR.x nodistro main" | sudo tee /etc/apt/sources.list.d/nodesource.list
sudo apt-get update
sudo apt-get install nodejs -y

Prior to August 2023: Previously versions of this answer involved the use of a series of setup_XX.x scripts that you'd run to install/update Node.js:

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

But as @eis pointed out, these scripts are no longer supported. To see the previous answers, please look at the edit history for this answer.

This can help:

$ sudo npm install -g n  
$ sudo npm cache clean -f  
$ sudo n stable  

also you can replase stable with latest.

NOTE: if $ node -v shows the old version, open a new shell.