From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2010-03-25T18:35:47+09:00
Subject: Re: hash problem

On Thu, Mar 25, 2010 at 10:29 AM, Adam Nelreth <nelreth@gmail.com> wrote:
> Ok - I know how to increase counter - bigger problem is with how to find
> this ip in table
>
> This is how I try to do this:
>
> if test.has_key?(ip) == true
>    print "ip in table"
> else
>    test[ip] = 1
> end
>

First of all, with the mechanism of the default value you don't need
to check for the key to set the initial value. It's done for you, as I
explained before:

h = Hash.new(0)
h[k] += 1

will set h[k] to 1 the first time, and increase it by one afterwards.

On the other hand, this does work for me:

irb(main):020:0> if h.has_key?("10.1.1.3") == true
irb(main):021:1> puts "found"
irb(main):022:1> end
found

Although for boolean comparison, the idiomatic way is to check against
the expression itself, instead of comparing to true, since in Ruby
anything that is not nil or false will be "truthy" in a boolean
expression

irb(main):017:0> if h.has_key?("10.1.1.3")
irb(main):018:1> puts "found"
irb(main):019:1> end
found

Jesus.