Hi I'm new to Ruby and regular expressions. I'm trying to use a regular expression to remove any zeros from the month or day in a date formatted like "02/02/1980" => "2/2/1980"
def m_d_y
strftime('%m/%d/%Y').gsub(/0?(\d{1})\/0?(\d{1})\//, $1 + "/" + $2 + "/" )
end
What is wrong with this regular expression?
Thanks.
"02/02/1980".gsub(/\b0/, '') #=> "2/2/1980"
\b is a zero-width marker for a word boundary, therefore \b0 cannot have a digit before the zero.
You can simply remove 0s in parts that ends with a slash.
Works for me
require "date"
class Date
def m_d_y
strftime('%m/%d/%Y').gsub(/0(\d)\//, "\\1/")
end
end
puts Date.civil(1980, 1, 1).m_d_y
puts Date.civil(1980, 10, 1).m_d_y
puts Date.civil(1980, 1, 10).m_d_y
puts Date.civil(1908, 1, 1).m_d_y
puts Date.civil(1908, 10, 1).m_d_y
puts Date.civil(1908, 1, 10).m_d_y
outputs
1/1/1980
10/1/1980
1/10/1980
1/1/1908
10/1/1908
1/10/1908
strftime('%m/%d/%Y').gsub(/0(\d)(?=\/)/, '\1').Why bother with regex when you can do this?
require "date"
class Date
def m_d_y
[mon, mday, year].join("/")
end
end
Try /(?<!\d)0(\d)/
"02/02/1980".gsub(/(?<!\d)0(\d)/,$1)
=> "2/2/1980"
'\1' (including quotes!) instead of $1.
The problem is that it won't match valid dates so your replacement will mangle valid strings. To fix:
Regex: (^|(?<=/))0
Replacement: ''
You say that Ruby is throwing a syntax error, so your problem lies before you have even reached the regexp. Probably because you aren't calling strftime on anything. Try:
def m_d_y
t = Time.now
t.strftime('%m/%d/%Y').gsub(/0?(\d{1})\/0?(\d{1})\//, $1 + "/" + $2 + "/" )
end
Then replace Time.now with a real time, then debug your regexp.
