Respond To

respond_to? checks whether an object can receive a method before calling it.

respond_to.rb

method_name = 
text = "ruby"

can_call = text.respond_to?(method_name)
result = can_call ? text.public_send(method_name) : "unavailable"

puts "method=#{method_name}"
puts "can_call=#{can_call}"
puts "result=#{result}"

method_name = 
text = "ruby"

can_call = text.respond_to?(method_name)
result = can_call ? text.public_send(method_name) : "unavailable"

puts "method=#{method_name}"
puts "can_call=#{can_call}"
puts "result=#{result}"

method_name = 
text = "ruby"

can_call = text.respond_to?(method_name)
result = can_call ? text.public_send(method_name) : "unavailable"

puts "method=#{method_name}"
puts "can_call=#{can_call}"
puts "result=#{result}"

respond to Checking `respond_to?` makes a dynamic call easier to explain and safer to trace.