New user - correct way to think and write code

ruby-talk
1

Hi - sorry to belabour the point, but I would appreciate any help or
guidance that anyone could give relative to the preferred way of writing
Ruby code. Thanks to some help earlier in the week from ruby-talk and from
Kastner I now have two additional ways of achieving the same result. I am
attempting to grasp the concept objects as well as learning ruby. Which
syntax (or style) should I focus on, or does it not matter. From my limited
understanding Kastner's example would seem to be a cleaner use of objects,
(or am I missing the point). Thanks for any help.

ashley

My starting point:

···

-----------------------------------------------------------
def require_number number_cur
puts number_cur
  reply = gets.to_i

while reply < 100000
    reply = reply + 1
    puts reply
end

if reply > 100
   true
   require_number 'Please enter a number less than 100: '
end
end
require_number 'Enter a number: '
-------------------------------------------------------------

Modified with input from Ruby-Talk

def require_number(prompt, max)
print prompt
   reply = gets.to_i
if reply >= max then reply = require_number "Please enter a number
   less than #{max}: ", max end
reply.upto(max) { |x| puts x }
end
require_number 'Please enter a number: ', 100000

---------------------------------------------------------------------

With further help from Kastner:

MAX = 100000

def get_number(prompt = "")
print prompt
# ruby methods return the last value
gets.to_i
end

def print_from_to(start, stop)
start.upto(stop) do |number|
   puts number
end
end

loop do
number = get_number "Please enter a number less than #{MAX}: "
next if number >= MAX
print_from_to(number, MAX)
break
end
-----------------------------------------------------------------------

2

Hi - sorry to belabour the point, but I would appreciate any help or
guidance that anyone could give relative to the preferred way of writing
Ruby code. Thanks to some help earlier in the week from ruby-talk and from
Kastner I now have two additional ways of achieving the same result. I am
attempting to grasp the concept objects as well as learning ruby. Which
syntax (or style) should I focus on, or does it not matter. From my limited
understanding Kastner's example would seem to be a cleaner use of objects,
(or am I missing the point). Thanks for any help.

...

With further help from Kastner:

MAX = 100000

def get_number(prompt = "")
print prompt
# ruby methods return the last value
gets.to_i
end

def print_from_to(start, stop)
start.upto(stop) do |number|
   puts number
end
end

loop do
number = get_number "Please enter a number less than #{MAX}: "
next if number >= MAX
print_from_to(number, MAX)
break
end

As far as I can see you logic is: read user input until it is valid
and then print from input to MAX. I would remove the printing from
the loop because that is much cleaner.

Kind regards

robert

···

2008/2/11, Ashley Wharton <ashleywnj@gmail.com>:

--
use.inject do |as, often| as.you_can - without end

3

I interpret Robert as saying that he prefers something like:

<code>
#! /usr/bin/env ruby -w

MAX = 100_000

def get_number(prompt = "")
    print prompt
    gets.to_i
end

def print_from_to(start, stop)
    start.upto(stop) { |number| puts number }
end

number = MAX
while number >= MAX
    number = get_number "Please enter a number less than #{MAX}: "
end
print_from_to(number, MAX)
</code>

So do I.

Regards, Morton

···

On Feb 11, 2008, at 7:24 AM, Robert Klemme wrote:

2008/2/11, Ashley Wharton <ashleywnj@gmail.com>:

...

With further help from Kastner:

MAX = 100000

def get_number(prompt = "")
print prompt
# ruby methods return the last value
gets.to_i
end

def print_from_to(start, stop)
start.upto(stop) do |number|
   puts number
end
end

loop do
number = get_number "Please enter a number less than #{MAX}: "
next if number >= MAX
print_from_to(number, MAX)
break
end

As far as I can see you logic is: read user input until it is valid
and then print from input to MAX. I would remove the printing from
the loop because that is much cleaner.

4

Thanks so much.

···

On Feb 11, 2008 7:33 PM, Morton Goldberg <m_goldberg@ameritech.net> wrote:

On Feb 11, 2008, at 7:24 AM, Robert Klemme wrote:

> 2008/2/11, Ashley Wharton <ashleywnj@gmail.com>:
>> ...
>
>> With further help from Kastner:
>>
>> MAX = 100000
>>
>> def get_number(prompt = "")
>> print prompt
>> # ruby methods return the last value
>> gets.to_i
>> end
>>
>> def print_from_to(start, stop)
>> start.upto(stop) do |number|
>> puts number
>> end
>> end
>>
>> loop do
>> number = get_number "Please enter a number less than #{MAX}: "
>> next if number >= MAX
>> print_from_to(number, MAX)
>> break
>> end
>
> As far as I can see you logic is: read user input until it is valid
> and then print from input to MAX. I would remove the printing from
> the loop because that is much cleaner.

I interpret Robert as saying that he prefers something like:

<code>
#! /usr/bin/env ruby -w

MAX = 100_000

def get_number(prompt = "")
   print prompt
   gets.to_i
end

def print_from_to(start, stop)
   start.upto(stop) { |number| puts number }
end

number = MAX
while number >= MAX
   number = get_number "Please enter a number less than #{MAX}: "
end
print_from_to(number, MAX)
</code>

So do I.

Regards, Morton

5

Actually I would have formulated it a bit different, i.e. applied the
loop check after reading:

#! /bin/env ruby

MAX = 100_000

def get_number(prompt = "")
  print prompt
  gets.to_i
end

def print_from_to(start, stop)
  start.upto(stop) { |number| puts number }
end

begin
  number = get_number "Please enter a number less than #{MAX}: "
end until (0...MAX).include? number

# alternative in one line:
# number = get_number "Please enter a number less than #{MAX}: " until
(0...MAX).include? number

print_from_to(number, MAX)

Kind regards

robert

···

2008/2/12, Morton Goldberg <m_goldberg@ameritech.net>:

On Feb 11, 2008, at 7:24 AM, Robert Klemme wrote:

> 2008/2/11, Ashley Wharton <ashleywnj@gmail.com>:
>> ...
>
>> With further help from Kastner:
>>
>> MAX = 100000
>>
>> def get_number(prompt = "")
>> print prompt
>> # ruby methods return the last value
>> gets.to_i
>> end
>>
>> def print_from_to(start, stop)
>> start.upto(stop) do |number|
>> puts number
>> end
>> end
>>
>> loop do
>> number = get_number "Please enter a number less than #{MAX}: "
>> next if number >= MAX
>> print_from_to(number, MAX)
>> break
>> end
>
> As far as I can see you logic is: read user input until it is valid
> and then print from input to MAX. I would remove the printing from
> the loop because that is much cleaner.

I interpret Robert as saying that he prefers something like:

<code>
#! /usr/bin/env ruby -w

MAX = 100_000

def get_number(prompt = "")
    print prompt
    gets.to_i
end

def print_from_to(start, stop)
    start.upto(stop) { |number| puts number }
end

number = MAX
while number >= MAX
    number = get_number "Please enter a number less than #{MAX}: "
end
print_from_to(number, MAX)
</code>

So do I.

--
use.inject do |as, often| as.you_can - without end