Install Drupal Console Using Composer

Change directory to Drupal site:

cd /path/to/drupal8.dev

Execute composer require command:

composer require drupal/console:~1.0 \
--prefer-dist \
--optimize-autoloader

Download using DrupalComposer project template

composer create-project \
drupal-composer/drupal-project:8.x-dev \
drupal8.dev \
--prefer-dist \
--no-progress \
--no-interaction

composer update drupal/console --with-dependencies