Takes a currency input and amount tendered, validates input, returns amount of change due.

Ruby_Fundamentals_Faizaan

puts "What is the amount due?"
amount_due = gets.chomp

if (amount_due[/^[1-9]\d*(\.\d+)?$/] == false) || (amount_due.scan(/\./).length > 1)
	puts "Warning: Invalid currency detected! Exiting..."
	abort
end

puts "What is the amount tendered?"
amount_tendered = gets.chomp

if (amount_tendered[/^[1-9]\d*(\.\d+)?$/] == false) || (amount_tendered.scan(/\./).length > 1)
	puts "Warning: Invalid currency detected! Exiting..."
	abort
end
amount_tendered = amount_tendered.to_f
amount_due = amount_due.to_f

if amount_tendered < amount_due  
	puts "WARNING: Customer still owes $#{sprintf('%.2f', (amount_due - amount_tendered))}! Exiting..."
	abort
end

puts "===Thank You!===", "The total change due is $#{sprintf('%.2f', (amount_tendered - amount_due))}", 
		 "", Time.now.strftime("%m/%d/%Y %I:%M%p" ) , "================" 


#How to improve:
#Shorten Conditions
#sprintf vs. printf