How to pass argument to anonymous function in hash?

Question

Ruby on Rails

There is ruby ​​code

a = {'hello' => proc { |hello| print hello}}
a['hello']('world')

On startup it says

/home/leonid/docs/prog/ruby/trys.rb:2: syntax error, unexpected '(', expecting end-of-input
a['chto-to']('world')

Answer 1

a = {'hello' => proc { |hello| print hello } }

a['hello'].call('world') # можно так
a['hello']['world'] # можно так
a['hello'].('world') # можно так