abinoda

Installing pg gem on macOS

If you're trying to install the postgresql gem pg and it is failing with the following error message:

Installing pg 1.2.3 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: ~/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/gems/pg-1.2.3/ext
~/.rbenv/versions/3.0.0/bin/ruby -I ~/.rbenv/versions/3.0.0/lib/ruby/3.0.0 -r ./siteconf20210125-97201-pycpo.rb extconf.rb

abinoda

Recursion

What is recursion?

A recursive function is a function that makes a call to itself.

To prevent infinite recursion, you need at least one branch (i.e. of an if/else statement) that does not make a recursive call. Branches without recursive calls are called base cases; branches with recursive calls are called recursive cases.

def factorial_recursive(n)
 if n == 0