Hel;p with Tip Calculator

Ruby
1

puts “What is the total?”
input = gets.chomp.to_i
puts “What percent do you want to tip?”
input2 = gets.chomp.to_i
percent = 100
tip = input2 * input * 0.01
puts “You should tip $#{tip}”

This is a tip calculator. I want it to work if the person enters $45 or
15%.

Right now, it would only return 0 because they are invalid numbers. It
would only work with an input of 15 or 45. I have really no clue how to
do that.

2

On Mon, 9 Aug 2010 00:46:29 +0900
Hd Pwnz0r [email protected] wrote:

Right now, it would only return 0 because they are invalid numbers. It
would only work with an input of 15 or 45. I have really no clue how
to do that.

Use

‘45 %’.sub(/%/, ‘’).strip
‘14 $’.sub(/[$]/, ‘’).strip

for that.

“strip” can remove unwanted trailing and leading blanks.
“sub” substitutes the charachters in the RE with an empty string
removing them.

Regards,
Andrei

3

On Sun, Aug 8, 2010 at 8:59 AM, Andrei B. [email protected]
wrote:

Use

‘45 %’.sub(/%/, ‘’).strip
‘14 $’.sub(/[$]/, ‘’).strip

More universally

input_string.gsub(/\D/, ‘’)

removes any non-[0-9] characters, including white space.

4

Hassan S. wrote:

On Sun, Aug 8, 2010 at 8:59 AM, Andrei B. [email protected]
wrote:

Use

‘45 %’.sub(/%/, ‘’).strip
‘14 $’.sub(/[$]/, ‘’).strip

More universally

input_string.gsub(/\D/, ‘’)

removes any non-[0-9] characters, including white space.

I get:

tax.rb:6:in <main>': undefined method gsub’ for 0:Fixnum
(NoMethodError)

When using that code.

As for Andrei, thanks, that’s a good quick fix.

5

On Tue, Aug 10, 2010 at 6:51 AM, Hd Pwnz0r
[email protected] wrote:

input_string.gsub(/\D/, ‘’)

tax.rb:6:in <main>': undefined method gsub’ for 0:Fixnum
(NoMethodError)

When using that code.

Yes, it works on strings – that was the problem you posed. If you
already have a number, it’s not going to include any symbols like
“$” or “%” in the first place.

6

or just

input_string.to_s.gsub(/\D/,‘’)
for number format permitted

2010/8/10 Hassan S. [email protected]

7

On Tue, Aug 10, 2010 at 6:38 PM, jason joo [email protected]
wrote:

or just

input_string.to_s.gsub(/\D/,‘’)
for number format permitted

Depending on what your actual numeric use case is :slight_smile:

$ irb

input = 9
=> 9
input.to_s.gsub(/\D/,‘’)
=> “9”
input = 9.095
=> 9.095
input.to_s.gsub(/\D/,‘’)
=> “9095”

8

aha, i forgot positive number and dot. then the regular expression
should
be /([-+]?\d*[.]?\d*)/

eg

if input_string =~ /([-+]?\d*[.]?\d*)/
input_string = $1
else
#have no number part
input_string = 0
end

9 => “9”
-9 => “-9”
-9.098 => “-9.098”

2010/8/11 Hassan S. [email protected]

9

At 2010-08-11 01:03AM, “jason joo” wrote:

[Note: parts of this message were removed to make it a legal post.]

aha, i forgot positive number and dot. then the regular expression should
be /([-+]?\d*[.]?\d*)/

The empty string matches that pattern (all your quantifiers allow zero
of the previous item). You want:

/[-+]?(?:\d+(\.\d*)?)|(?:\d*\.\d+)/

where there must be at least one digit.