Question

When developing & debugging, I sometimes wish I could write a 1-liner that dumped the names, types & values of a bunch of variables. The problem is I don’t know how to access the name of a variable, if I can at all.

Here is a first attempt:

foo = 1
bar = "42"
baz = Hash.new

[foo, bar, baz].each do |v|
    puts "#{v.???} = (#{v.class}) #{v}"
    end

I’d like the output of this program to be something like:

foo = (Fixnum) 1 
bar = (String) 42 
baz = (Hash) ...

I don’t know what ??? should be above. Can this be done?

Answer 1

foo = 1
bar = "42"
baz = Hash.new

%w(foo bar baz).each do |vn|
    v = eval(vn)
    puts "#{vn} = (#{v.class}) #{v}"
end

But this, of course, doesn’t help you if you want a method with 1 argument.