How do I dump an object's fields to the consol

Question

When I'm running a simple Ruby script, what's the easiest way to dump an object's fields to the console?

I'm looking for something similar to PHP's print_r() that will work with arrays as well.

Answer 1

p object

Ruby doc for p.

p(*args) public

For each object, directly writes obj.inspect followed by a newline to the program’s standard output.

Answer 2

If you're looking for just the instance variables in the object, this might be useful:

obj.instance_variables.map do |var|
  puts [var, obj.instance_variable_get(var)].join(":")
end

or as a one-liner for copy and pasting:

obj.instance_variables.map{|var| puts [var, obj.instance_variable_get(var)].join(":")}

Answer 3

If you want to print an already indented JSON:

require 'json'
...
puts JSON.pretty_generate(JSON.parse(object.to_json))

Answer 4

The to_yaml method seems to be useful sometimes:

$foo = {:name => "Clem", :age => 43}

puts $foo.to_yaml

returns

--- 
:age: 43
:name: Clem

(Does this depend on some YAML module being loaded? Or would that typically be available?)

Answer 5

puts foo.to_json

might come in handy since the json module is loaded by default

Answer 6

Possibly:

puts variable.inspect