Difference between Array and Map

Last Updated : 18 Sep, 2023

Array:

An array is a collection of items stored at contiguous memory locations. The idea is to store multiple items of the same type together. This makes it easier to calculate the position of each element by simply adding an offset to a base value, i.e., the memory location of the first element of the array (generally denoted by the name of the array).
The diagrammatic representation of the Array is given below:

Program 1:
Below is an illustration of a 1D array:

Output:

6 10 5 0

Program 2:
Below is an illustration of a 2D array:

C++

// C++ program to illustrate 1D array #include <bits/stdc++.h> using namespace std; // Driver Code int main() {  // A 2D array with 3 rows and  // 2 columns  int x[3][2] = { { 0, 1 }, { 2, 3 }, { 4, 5 } };  // Print each array element value  // Traverse row  for (int i = 0; i < 3; i++) {  // Traverse column  for (int j = 0; j < 2; j++) {  // Print element  cout << "Element at x[" << i  << "][" << j  << "]: ";  cout << x[i][j] << endl;  }  }  return 0; }

Java

// Java program to illustrate 1D array import java.util.*; class GFG{ // Driver Code public static void main(String[] args) {  // A 2D array with 3 rows and  // 2 columns  int x[][] = { { 0, 1 }, { 2, 3 }, { 4, 5 } };  // Print each array element value  // Traverse row  for (int i = 0; i < 3; i++)  {  // Traverse column  for (int j = 0; j < 2; j++)   {  // Print element  System.out.print("Element at x[" + i +   "][" + j + "]: ");  System.out.print(x[i][j] + "\n");  }  } } } // This code is contributed by Princi Singh

Python3

# Python3 program to illustrate 1D array # Driver Code if __name__ == '__main__': # A 2D array with 3 rows and # 2 columns x = [[0, 1], [2, 3], [4, 5]]; # Print each array element value # Traverse row for i in range(3): # Traverse column for j in range(2): # Print element print("Element at x[" , i , "][" , j , "]: ", end = ""); print(x[i][j]); # This code is contributed by sapnasingh4991

// C# program to illustrate 1D array using System; class GFG{ // Driver Code public static void Main(String[] args) {  // A 2D array with 3 rows and  // 2 columns  int [,]x = { { 0, 1 }, { 2, 3 }, { 4, 5 } };  // Print each array element value  // Traverse row  for (int i = 0; i < 3; i++)  {  // Traverse column  for (int j = 0; j < 2; j++)   {  // Print element  Console.Write("Element at x[" + i +   "," + j + "]: ");  Console.Write(x[i,j] + "\n");  }  } } } // This code is contributed by Princi Singh

JavaScript

 // JavaScript program to illustrate 1D array    // A 2D array with 3 rows and  // 2 columns  let x = [ [ 0, 1 ], [ 2, 3 ], [ 4, 5 ] ];    // Print each array element value  // Traverse row  for (let i = 0; i < 3; i++)  {    // Traverse column  for (let j = 0; j < 2; j++)  {    // Print element  process.stdout.write("Element at x[" + i +  "][" + j + "]: ");  console.log(x[i][j]);  }  }

Output

Element at x[0][0]: 0 Element at x[0][1]: 1 Element at x[1][0]: 2 Element at x[1][1]: 3 Element at x[2][0]: 4 Element at x[2][1]: 5

Map:

A map is an associative container that stores elements in a mapped fashion. Each element has a key value and a mapped value. No two mapped values can have equal key values.

The diagrammatic representation of Map is given below:

Program 1:
Below is an illustration of a map:

C++

// C++ program to illustrate Map #include <bits/stdc++.h> using namespace std; // Driver Code int main() {  // Empty map container  map<int, int> gquiz1;  // Insert elements in Map  gquiz1.insert(pair<int, int>(1, 40));  gquiz1.insert(pair<int, int>(2, 30));  gquiz1.insert(pair<int, int>(3, 60));  // Iterator to iterate Map  map<int, int>::iterator itr;  cout << "\nThe map gquiz1 is : \n";  cout << "\tKEY\tELEMENT\n";  // Print map gquiz1  for (itr = gquiz1.begin();  itr != gquiz1.end(); ++itr) {  cout << '\t' << itr->first  << '\t' << itr->second  << '\n';  }  return 0; }

Java

// Java program to illustrate Map import java.util.*; class GFG{ // Driver Code public static void main(String[] args) {  // Empty map container  HashMap<Integer,  Integer> gquiz1 = new HashMap<Integer,  Integer>();  // Insert elements in Map  gquiz1.put(1, 40);  gquiz1.put(2, 30);  gquiz1.put(3, 60);  // Iterator to iterate Map  Iterator<Map.Entry<Integer,   Integer>> itr = gquiz1.entrySet().  iterator();  System.out.print("\nThe map gquiz1 is : \n");  System.out.print("KEY\tELEMENT\n");  // Print map gquiz1  while(itr.hasNext())   {  Map.Entry<Integer,   Integer> entry = itr.next();  System.out.print('\t' + entry.getKey()  + "\t" + entry.getValue()+ "\n");  } } } // This code is contributed by shikhasingrajput

Python3

# Python3 program to illustrate Map # Driver Code if __name__ == '__main__': # Empty map container gquiz1 = dict() # Insert elements in Map gquiz1[1] = 40 gquiz1[2] = 30 gquiz1[3] = 60 print("\nThe map gquiz1 is : ") print("KEY\tELEMENT") for x, y in gquiz1.items(): print(x, "\t", y) # This code is contributed by Rajput-Ji

// C# program to illustrate Map using System; using System.Collections.Generic; class GFG{ // Driver Code public static void Main(String[] args) {    // Empty map container  Dictionary<int,  int> gquiz1 = new Dictionary<int,  int>();    // Insert elements in Map  gquiz1.Add(1, 40);  gquiz1.Add(2, 30);  gquiz1.Add(3, 60);    Console.Write("\nThe map gquiz1 is : \n");  Console.Write("\tKEY\tELEMENT\n");    // Print map gquiz1  foreach(KeyValuePair<int,   int> entry in gquiz1)  {  Console.Write("\t" + entry.Key +   "\t" + entry.Value + "\n");  } } } // This code is contributed by Amit Katiyar

JavaScript

// JavaScript program to illustrate Map let gquiz1 = new Map(); // Insert elements in Map gquiz1.set(1, 40); gquiz1.set(2, 30); gquiz1.set(3, 60); // Iterator to iterate Map let itr; console.log("\nThe map gquiz1 is : \n"); console.log("\tKEY\tELEMENT\n"); // Print map gquiz1 for (itr of gquiz1.entries()) {  console.log(`\t${itr[0]}\t${itr[1]}\n`); } // This code is contributed by akashish__

Output

The map gquiz1 is : KEY ELEMENT 1 40 2 30 3 60

Program 2:
Below is an illustration of an unordered map:

C++

// C++ program to illustrate Map #include <bits/stdc++.h> using namespace std; // Driver Code int main() {  // Declaring umap of <string, int>  // type key will be of string and  // mapped value will be of double  unordered_map<string, int> umap;  // Insert values by using [] operator  umap["GeeksforGeeks"] = 10;  umap["Practice"] = 20;  umap["Contribute"] = 30;  // Traversing an unordered map  // and print the key-value pairs  for (auto x : umap)  cout << x.first << " "  << x.second << endl;  return 0; }

Java

// Java program to illustrate Map import java.util.*; class GFG{ // Driver Code public static void main(String[] args) {    // Declaring umap of <String, int>  // type key will be of String and  // mapped value will be of double  HashMap<String,   Integer> umap = new HashMap<>();  // Insert values by using [] operator  umap.put("GeeksforGeeks", 10);  umap.put("Practice", 20);  umap.put("Contribute", 30);  // Traversing an unordered map  // and print the key-value pairs  for(Map.Entry<String,  Integer> x : umap.entrySet())  System.out.print(x.getKey() + " " +  x.getValue() + "\n"); } } // This code is contributed by amal kumar choubey

Python3

class GFG : # Driver Code @staticmethod def main( args) : # Declaring umap of <String, int> # type key will be of String and # mapped value will be of double umap = dict() # Insert values by using [] operator umap["GeeksforGeeks"] = 10 umap["Practice"] = 20 umap["Contribute"] = 30 # Traversing an unordered map # and print the key-value pairs for key,value in umap.items() : print(key + " " + str(umap.get(key)) + "\n", end ="") if __name__=="__main__": GFG.main([]) # This code is contributed by aadityaburujwale.

// C# program to illustrate Map using System; using System.Collections.Generic; class GFG{  // Driver Code  public static void Main(String[] args)  {  // Declaring umap of <String, int>  // type key will be of String and  // mapped value will be of double  Dictionary<String, int> umap = new Dictionary<String,   int>();  // Insert values by using [] operator  umap.Add("Contribute", 30);  umap.Add("GeeksforGeeks", 10);  umap.Add("Practice", 20);   // Traversing an unordered map  // and print the key-value pairs  foreach(KeyValuePair<String, int> x in umap)  Console.Write(x.Key + " " + x.Value + "\n");  } } // This code is contributed by Rajput-Ji

JavaScript

// Declaring a Map with string keys and integer values let umap = new Map(); // Inserting key-value pairs umap.set("GeeksforGeeks", 10); umap.set("Practice", 20); umap.set("Contribute", 30); // Traversing the Map and printing key-value pairs for (let [key, value] of umap) {  console.log(key + " " + value); }

Output

Contribute 30 GeeksforGeeks 10 Practice 20

Program 3:
Below is an illustration of a multimap:

C++

// C++ program to illustrate Multimap #include <bits/stdc++.h> using namespace std; // Driver Code int main() {  // Empty multimap container  multimap<int, int> gquiz1;  // Insert elements  gquiz1.insert(pair<int, int>(1, 40));  gquiz1.insert(pair<int, int>(2, 30));  // Iterator  multimap<int, int>::iterator itr;  cout << "\nThe multimap gquiz1 is : \n";  cout << "\tKEY\tELEMENT\n";  // Print multimap gquiz1  for (itr = gquiz1.begin();  itr != gquiz1.end(); ++itr) {  cout << '\t' << itr->first  << '\t' << itr->second  << '\n';  }  return 0; }

Java

import java.util.*; public class Main {  public static void main(String[] args) {  // Empty multimap container  Map<Integer, Integer> gquiz1 = new TreeMap<>();  // Insert elements  gquiz1.put(1, 40);  gquiz1.put(2, 30);  // Iterator  Iterator<Map.Entry<Integer, Integer>> itr = gquiz1.entrySet().iterator();  System.out.println("The multimap gquiz1 is : ");  System.out.println("\tKEY\tELEMENT");  // Print multimap gquiz1  while (itr.hasNext()) {  Map.Entry<Integer, Integer> entry = itr.next();  System.out.println("\t" + entry.getKey() + "\t" + entry.getValue());  }  } }

Python3

# Python Program to illustrate Multimap # Empty multimap container gquiz1 = {} # Insert elements gquiz1[1] = 40 gquiz1[2] = 30 # Iterator itr = gquiz1.items() print("\nThe multimap gquiz1 is : ") print("\tKEY\tELEMENT") # Print multimap gquiz1 for (key, value) in itr: print('\t', key, '\t', value) # This code is contributed by akashish__

// C# program to illustrate Multimap using System; using System.Collections.Generic; public class GFG  {  // Driver Code  public static void Main()  {  // Empty multimap container  SortedDictionary<int, int> gquiz1  = new SortedDictionary<int, int>();  // Insert elements  gquiz1.Add(1, 40);  gquiz1.Add(2, 30);  // Iterator  SortedDictionary<int, int>.Enumerator itr;  Console.WriteLine("\nThe multimap gquiz1 is : ");  Console.WriteLine("\tKEY\tELEMENT");  // Print multimap gquiz1  for (itr = gquiz1.GetEnumerator();  itr.MoveNext();) {  Console.WriteLine("\t{0}\t{1}", itr.Current.Key,  itr.Current.Value);  }  } }

JavaScript

// JavaScript Program to illustrate Multimap // Empty multimap container let gquiz1 = {}; // Insert elements gquiz1[1] = 40; gquiz1[2] = 30; // Iterator let itr = Object.entries(gquiz1); console.log("\nThe multimap gquiz1 is : "); console.log("\tKEY\tELEMENT"); // Print multimap gquiz1 for (let [key, value] of itr) {  console.log('\t', key, '\t', value); } // This code is contributed by akashish__

Output

The multimap gquiz1 is : KEY ELEMENT 1 40 2 30

Program 4:
Below is an illustration of an unordered multimap:

C++

// C++ program to illustrate // unordered multimap #include <bits/stdc++.h> using namespace std; // Driver Code int main() {  // Empty initialization  unordered_multimap<string, int> umm1;  // Initialization by initializer list  unordered_multimap<string, int> umm2(  { { "apple", 1 },  { "ball", 2 },  { "apple", 10 },  { "cat", 7 },  { "dog", 9 },  { "cat", 6 },  { "apple", 1 } });  // Traversing an unordered_multimap  // and print the elements stored  for (auto x : umm2) {  cout << x.first << " "  << x.second << endl;  }  return 0; }

Java

import java.util.*; public class Main {  public static void main(String[] args)  {  // Initialization by initializer list  HashMap<String, ArrayList<Integer> >  umm2 = new HashMap<>() {  {  put("apple",  new ArrayList<>(  Arrays.asList(1, 10, 1)));  put("ball",  new ArrayList<>(  Collections.singletonList(2)));  put("cat", new ArrayList<>(  Arrays.asList(7, 6)));  put("dog",  new ArrayList<>(  Collections.singletonList(9)));  }  };  // Traversing the hashmap and print the elements  // stored  for (Map.Entry<String, ArrayList<Integer> > entry :  umm2.entrySet()) {  String key = entry.getKey();  ArrayList<Integer> values = entry.getValue();  for (int value : values) {  System.out.println(key + " " + value);  }  }  } }

Python3

from collections import defaultdict # Initializing a defaultdict with  # lists as default values GFG = defaultdict(list) # Adding key-value pairs to the defaultdict GFG["apple"] = [1, 10, 1] GFG["ball"] = [2] GFG["cat"] = [7, 6] GFG["dog"] = [9] # Traversing the defaultdict and  # printing the elements stored for key, values in GFG.items(): for value in values: print(key, value)

using System; using System.Collections.Generic; class Program {  static void Main(string[] args)  {  // Initialization by initializer list  var umm2  = new SortedDictionary<string, List<int> >() {  { "apple", new List<int>(){ 1, 10, 1 } },  { "ball", new List<int>(){ 2 } },  { "cat", new List<int>(){ 7, 6 } },  {  "dog", new List<int>() { 9 }  }  };  // Traversing the sorted dictionary and print the  // elements stored  foreach(  KeyValuePair<string, List<int> > entry in umm2)  {  string key = entry.Key;  List<int> values = entry.Value;  foreach(int value in values)  {  Console.WriteLine(key + " " + value);  }  }  } } // This code is contributed by sarojmcy2e

JavaScript

// Javascript code addition  // Initialization of the HashMap const umm2 = new Map([  ["apple", [1, 10, 1]],  ["ball", [2]],  ["cat", [7, 6]],  ["dog", [9]] ]); // Traversing the hashmap and print the elements stored for (let [key, values] of umm2) {  values.forEach(value => {  console.log(key + " " + value);  }); } // The code is contributed by Nidhi goel.

Output

apple 1 apple 10 apple 1 ball 2 cat 6 cat 7 dog 9