From: Chad Perrin <code@...>
Date: 2011-08-25T02:58:23+09:00
Subject: Re: eliminate duplicate key based on value

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On Thu, Aug 25, 2011 at 02:12:34AM +0900, Lucky Nl wrote:
>=20
> i have hash as below
>=20
> list =3D {"18" =3D> 1,"15" =3D> 2,"15" =3D> 3,"17" =3D> 4,"18" =3D> 5}

Let's see what irb does with that:

    irb
    >> list =3D {"18" =3D> 1,"15" =3D> 2,"15" =3D> 3,"17" =3D> 4,"18" =3D> =
5}
    =3D> {"17"=3D>4, "15"=3D>3, "18"=3D>5}

As you can see, subsequent assignments of a value to a particular key
when that key has already been used simply overwrite the value already
established for that key.

Thus, if you want only the 2 value for the "15" key to exist, you need to
set the 2 value last.  If you set the 3 value last, it overwrites the 2
value.  This is because there is only one of each key in a hash.  How
would you be able to access a particular value, otherwise?

I hope that helps.

--=20
Chad Perrin [ original content licensed OWL: http://owl.apotheon.org ]

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