From: "David A. Black" <dblack@...>
Date: 2008-07-27T08:07:46+09:00
Subject: Re: Convert month string to number

Hi --

On Sun, 27 Jul 2008, Adgar Marks wrote:

> Hi all,
>
> I use linux OS. I would like to convert a file with the folloing format:
> -rw-r--r-- 1 student student 11289 26. Jul 22:41 listing.txt
>
> into FileName, Year, Month, Day
>
> In order to do this, i would like to convert the month string from "Jul"
> in to the number 7.
>
> I wrote the following code:
>
> def ConvertMonthToNumber(MonthStr)
>        case MonthStr
>                when "Jan"  then  1
>                when "Feb"  then  2
>                when "Mar"  then  3
>                when "Apr"  then  4
>                when "May"  then  5
>                when "Jun"  then  6
>                when "Jul"  then  7
>                when "Aug"  then  8
>                when "Sep"  then  9
>                when "Okt"  then 10
>                when "Nov"  then 11
>                when "Dec"  then 12
>        end
> end
>
> when i run this code, i get the following error:
> SortList.rb:7: formal argument cannot be a constant
> def ConvertMonthToNumber(MonthStr)
>                                 ^
>
> My questions are:
> 1. Is there already a function that does in Ruby?
> 2. How to correct this bug?

1. require 'date'
    Date::ABBR_MONTHNAMES.index("Jun")   # 6

2. Use a variable instead of a constant as your parameter. Variables
start with lowercase letters or _ (underscore).


David

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