Actually, you would rather write this as :

%hash = (one => 1 , two => 2, three => 3, four => 4);

since one of the nice point of "=>" is that it allows to use a bareword on it's left side without strict protesting about it (well it's obvious here that you want a string on this side so it's nice not having to be explicit about it in my opinion, => is a nice syntaxic sugared comma).

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Jedaļ