Iterate through LinkedHashMap using an Iterator in Java

LinkedHashMap is a pre-defined class in java like HashMap. The only difference between LinkedHashMap and HashMap is LinkedHashMap preserve insertion order while HashMap does not preserve insertion order. The task is to iterate through a LinkedHashMap using an Iterator. We use the Iterator object to iterate through a LinkedHashMap.

Example

Input: Key - 2 : Value - 6
 Key - 3 : Value - 4
 Key - 6 : Value - 5
 Key - 4 : Value - 10
 Key - 5 : Value - 6

Output:

Key = Value
2 = 6
3 = 4
6 = 5
4 = 10
5 = 6

Algorithm : 

1. Create a LinkedHashMap and add key, value pairs.

2. we convert our LinkedHashMap to entrySet using,

Set s = lhm.entrySet();

3. we define iterator for our set.    

Iterator it=s.iterator();

4. Using while loop we iterate through our linkedHashMap. 

while(it.hasNext()) 
 System.out.println(it.next()); 

Implementation

key=Value
2=6
3=4
6=8
4=10
5=6

Time Complexity: O(n).