For general cases, when one of them will work, which is better to use, a hash map or a hash table?

Question

I sometimes used hash tables in several languages, but I just stumbled upon a Java map while looking at some code. I checked the differences in this SO question , which expressed this very clearly. My question is this:

• When anyone can work for you, which is better to use? Which one to choose if you are not working with zeros / threads ...?

• Which one is more commonly used / is more standard?

Answer 1

• , HashMap, , Hashtable
• , HashMap . Hashtable concurrency .

Answer 2

Hashtable . JDK 1.0. 1.2, , Hashtable , . , ​​ ( , , YMMV).

, , Hashtable, . , HashMap . , "null null" .

StringBuffer, StringBuilder.

, : HashMap: . Hashtable - . , Hashtable Collections.synchronizedMap().

Answer 3

HashMap, .

Answer 4

HashMap, Hashtable , , .

Answer 5

Hashtable Java, HashMap Framework Collections, Java 2. :

• Hashtable , HashMap - . , .

a HashMap , Hashtable - .

a HashMapallows zero values ​​in it, but Hashtablenot.

So you can go with HashMapfor any new code. If you need synchronization, you better off Collections.synchronizedMap(HashMap). See this similar SO threa d for more ideas.

Answer 6

HashMap for local variables or method parameters, since they are thread safe.