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HashMap - Hashtable

sr shashidhar

Joined: Jan 17, 2013
Posts: 27
Hi frndz,

HashMap permits null values and null key,

HashTable doesn't allow key or value as null... why...?

Thanks in advance
Jesper de Jong
Java Cowboy
Saloon Keeper

Joined: Aug 16, 2005
Posts: 14074

Because that's just how those classes were designed. There's really no special reason.

You should always use HashMap and not Hashtable. Hashtable is a legacy collection class, which has more or less been replaced by HashMap since Java 1.2 (when the Collections Framework was added to Java).

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It is sorta covered in the JavaRanch Style Guide.
subject: HashMap - Hashtable
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