LinkedHashMap is a Hash table and linked list implementation of the Map interface. In LinkedHashMap order of key-value pair depends on the order in which keys were inserted into the map. Insertion order does not affect if a key is reinserted into the map.
Example:
Input:
Key: 1
Value : 1221
Key: 2
Value : 2112
Output:
Keys : [1,2]
Values : [1221,2112]
Key-Value pairs : [1=1221, 2=2112]
Methods Use:
- put(Key, Value): First parameter as key and second parameter as Value.
- keySet(): Creates a set out of the key elements contained in the hash map.
- values(): Create a set out of the values in the hash map.
Approach:
- Create two-variable named as Key and Value
- Accept the input from user in Key and in Value
- Use put() method to add Key-Value pair inside the LinkedHashMap
Below is the implementation of the above approach:
Java
// Java Program to add key-value // pairs to LinkedHashMapimport java.util.*;public class Main { public static void main(String[] args) { // create an instance of LinkedHashMap LinkedHashMap<Integer, Integer> map = new LinkedHashMap<Integer, Integer>(); int num, key, val; num = 2; for (int i = 0; i < num; i++) { // Taking inputs from user key = i + 1; val = key * 10; // Add mappings using put method map.put(key, val); } // Displaying key System.out.println("Keys: " + map.keySet()); // Displaying value System.out.println("Values: " + map.values()); // Displaying key-value pair System.out.println("Key-Value pairs: " + map.entrySet()); }} |
Output
Keys: [1, 2] Values: [10, 20] Key-Value pairs: [1=10, 2=20]
Time Complexity: O(1)
