Unable to self-update composer?

Question

I am trying to update composer with no luck!

What I have tried:

$ composer self-update

[InvalidArgumentException]

Answer 1

Install the latest Composer by Following steps:

Uninstalling Composer

sudo apt-get remove composer

Run following commands

php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
php -r "if (hash_file('sha384', 'composer-setup.php') === '8a6138e2a05a8c28539c9f0fb361159823655d7ad2deecb371b04a83966c61223adc522b0189079e3e9e277cd72b8897') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"
php composer-setup.php

Install Composer in /usr/bin dir to run composer from anywhere

sudo php composer-setup.php --install-dir=/usr/bin --filename=composer

Remove the installer

php -r "unlink('composer-setup.php');"

To check or self update

composer self-update