Linked Questions
93 questions linked to/from What are the differences between a HashMap and a Hashtable in Java?
22
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3
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How is Hashtable different to Hashmap [duplicate]
Possible Duplicate:
Differences between HashMap and Hashtable?
I've seen hash tables and hash maps used in different code but they look like they do the same thing. Is there a difference between ...
- 255
5
votes
5
answers
3k
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difference between hashmap and hashtable| [duplicate]
Possible Duplicate:
Differences between HashMap and Hashtable?
I went to an interview the other day interviewer asked me under which situation will there be a problem to use hashmap rather then ...
- 2,597
2
votes
6
answers
2k
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Java hashtable or hashmap? [duplicate]
I've been researching to find a faster alternative to list. In an algorithm book, hashtable seems to be the fastest using separate chaining. Then I found that java has an implementation of hashtable ...
- 653
3
votes
0
answers
1k
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ConcurrentHashMap and Hash table difference [duplicate]
I am new to Java and stackoverflow and am seeking answer from experienced folks, who have worked on Collections Framework.
I read that hashTable is thread safe and so is concurrentHashMap, but a ...
- 2,140
1
vote
0
answers
396
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HashMap vs Hashtable (get & put) Implementation [duplicate]
I've been going through Java API java.util.HashMap and java.util.Hashtable
I've understood the internal implementation of get(Key k) and put(Key k, Value v)methods of HashMap, and Hashtableseems ...
- 486
1159
votes
18
answers
600k
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What does 'synchronized' mean?
I have some questions regarding the usage and significance of the synchronized keyword.
What is the significance of the synchronized keyword?
When should methods be synchronized?
What does it mean ...
- 27.7k
624
votes
11
answers
451k
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Java Class that implements Map and keeps insertion order?
I'm looking for a class in java that has key-value association, but without using hashes. Here is what I'm currently doing:
Add values to a Hashtable.
Get an iterator for the Hashtable.entrySet().
...
- 6,325
299
votes
9
answers
206k
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Java List.add() UnsupportedOperationException
I try to add objects to a List<String> instance but it throws an UnsupportedOperationException.
Does anyone know why?
My Java code:
String[] membersArray = request.getParameterValues('members')...
- 4,414
131
votes
20
answers
140k
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When to use Comparable and Comparator
I have a list of objects I need to sort on a field, say Score. Without giving much thought I wrote a new class that implements Comparator, that does the task and it works.
Now looking back at this, ...
- 2,369
140
votes
14
answers
373k
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Java: how to convert HashMap<String, Object> to array
I need to convert a HashMap<String, Object> to an array; could anyone show me how it's done?
- 58.2k
112
votes
7
answers
183k
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Difference between Dictionary and Hashtable [duplicate]
Possible Duplicate:
Why is Dictionary preferred over Hashtable in C#?
What is the difference between Dictionary and Hashtable. How to decide which one to use?
- 9,616
120
votes
6
answers
41k
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HashMap Java 8 implementation
As per the following link document: Java HashMap Implementation
I'm confused with the implementation of HashMap (or rather, an enhancement in HashMap). My queries are:
Firstly
static final int ...
- 2,190
85
votes
13
answers
87k
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Simplest and understandable example of volatile keyword in Java
I'm reading about volatile keyword in Java and completely understand the theory part of it.
But, what I'm searching for is, a good case example, which shows what would happen if variable wasn't ...
- 1,187
94
votes
2
answers
105k
views
ConcurrentHashMap and Hashtable in Java [duplicate]
What is the difference between a ConcurrentHashMap and a Hashtable in Java?
Which is more efficient for threaded applications?
- 10.4k
54
votes
6
answers
28k
views
Difference between Hashtable and Collections.synchronizedMap(HashMap)
As far as I know, java.util.Hashtable synchronizes each and every method in the java.util.Map interface, while Collections.synchronizedMap(hash_map) returns a wrapper object containing synchronized ...
- 10.7k