Why do this Ruby object have both to_s and inspect methods that appear to do the same thing?

Question

Why do this Ruby object both a to_s and inspect methods that appear to do the same thing?

The p method calls inspect and puts/print calls to_s for representing the object.

If I run

class Graph   def initialize     @nodeArray = Array.new     @wireArray = Array.new   end   def to_s # called with print / puts     "Graph : #{@nodeArray.size}"   end   def inspect # called with p     "G"   end end  if __FILE__ == $0   gr = Graph.new   p gr   print gr   puts gr end 

I get

G Graph : 0 Graph : 0 

• Then, why does Ruby have two functions do the same thing? What is the difference between to_s and inspect?
• And what's the difference between puts, print, and p?

If I comment out the to_s or inspect function, I get as follows.

#<Graph:0x100124b88> #<Graph:0x100124b88> 

Answer 1

inspect is used more for debugging and to_s for end-user or display purposes.

For example, [1,2,3].to_s and [1,2,3].inspect produce different output.