Update HashTable_vs_HashMap.md

deepak-malik · web-flow · commit 4e599e8fe8a0 · 2017-10-30T10:53:57.000-07:00
diff --git a/src/com/deepak/data/structures/Hashing/HashTable_vs_HashMap.md b/src/com/deepak/data/structures/Hashing/HashTable_vs_HashMap.md
@@ -1,38 +1,42 @@
-``` HashTable v/s HashMap
+### HashTable v/s HashMap
+
 Before this, I would suggest to go through the topic Iterator V/S Enumeration here.
 
 There are some significant factors that makes both of these data structures different
 
-1. Synchronization or Thread Safety
-- This is the most important difference between the two. 
-- Hash tables are synchronized and thread safe whereas Hash maps are not.
+**1. Synchronization or Thread Safety**
+  - This is the most important difference between the two. 
+  - Hash tables are synchronized and thread safe whereas Hash maps are not.
 
-2. Null keys and Null values
-- HashMap allows one null key and multiple null values, whereas hash table doesn't allow neither null values not null keys.
+**2. Null keys and Null values**
+  - HashMap allows one null key and multiple null values, whereas hash table doesn't allow neither null values not null keys.
 
-3. Iterating the Values
-- Values in hash map are iterated using an iterator, whereas in hash table values are iterated using enumerator.
-- Only Vector other then hash table uses enumerator to iterate through elements. 
+**3. Iterating the Values**
+  - Values in hash map are iterated using an iterator, whereas in hash table values are iterated using enumerator.
+  - Only Vector other then hash table uses enumerator to iterate through elements. 
 
-4. Fail Fast Iterator
-- Iterator in hash map is fail fast iterator, whereas enumerator for hash table is not.
-- If hash table is structurally modified at any time after the iterator is created other then iterators own remove method, then it will throw Concurrent Modification exception.
-- Structural modification means adding or removing elements from the collection.
+**4. Fail Fast Iterator**
+  - Iterator in hash map is fail fast iterator, whereas enumerator for hash table is not.
+  - If hash table is structurally modified at any time after the iterator is created other then iterators own remove method, then it will throw Concurrent Modification exception.
+  - Structural modification means adding or removing elements from the collection.
 
-5. Super class and Legacy
-- HashTable is a subclass of Dictionary, which is now obsolete from JDK 1.7
+**5. Super class and Legacy**
+  - HashTable is a subclass of Dictionary, which is now obsolete from JDK 1.7
 
-6. Performance 
-- HashMap is much faster and uses less memory because it is not synchronized. 
+**6. Performance**
+  - HashMap is much faster and uses less memory because it is not synchronized. 
 
-Similarities :
-1. Order of elements 
-- Cannot be guaranteed, because both of these work based on the hashing logic. use Linked Hash map for that
-2. Both of them comes from Map interface.
-3. Both provides constant time for performance for put and get methods, assuming that objects are distributed uniformly.
-4. Both works on the principle of hashing
+**Similarities :**
+```
+- Order of elements cannot be guaranteed, because both of these work based on the hashing logic. use Linked Hash map for that
+- Both of them comes from Map interface.
+- Both provides constant time for performance for put and get methods, assuming that objects are distributed uniformly.
+- Both works on the principle of hashing
+```
 
-When to use?
+**When to use?**
+```
 Avoid using HashTable, as they are obsolete now, ConcurrentHashMap has replaced it.
 Single threaded apps - use HashMap
- 
+```
+ 
