Cry from the heart, composer install error, what should I do?

Question

Composer

When executed in the console, it
php composer.phar install
gives:

PHP Fatal error:  Class 'Phar' not found in composer.phar on line 23
Content-type: text/html
Fatal error:  Class 'Phar' not found in composer.phar on line 23

actually line 23:
Phar::mapPhar('composer.phar');
Help me out.

Answer 1

phar extension not included