Python

In Python, the built-in dict type serves as a map. To create a map with initial key-value pairs, you can simply use curly braces {} and separate the key-value pairs with colons :. Here’s an example:

my_map = {'a': 1, 'b': 2, 'c': 3}

You can access the values by using the keys:

print(my_map['a'])  # Output: 1
print(my_map['b'])  # Output: 2
print(my_map['c'])  # Output: 3

Java

In Java, you can use the HashMap class from the java.util package to create a map. To initialize a HashMap with key-value pairs, you can use the put() method. Here’s an example:

import java.util.HashMap;
import java.util.Map;

public class Main {
    public static void main(String[] args) {
        Map<String, Integer> myMap = new HashMap<>();
        
        myMap.put("a", 1);
        myMap.put("b", 2);
        myMap.put("c", 3);
        
        System.out.println(myMap.get("a"));  // Output: 1
        System.out.println(myMap.get("b"));  // Output: 2
        System.out.println(myMap.get("c"));  // Output: 3       
    }
}

JavaScript

In JavaScript, you can use the built-in Map object to create a map with initial key-value pairs. To add key-value pairs, you can use the set() method. Here’s an example:

let myMap = new Map();

myMap.set('a', 1);
myMap.set('b', 2);
myMap.set('c', 3);

console.log(myMap.get('a'));  // Output: 1
console.log(myMap.get('b'));  // Output: 2
console.log(myMap.get('c'));  // Output: 3

Conclusion

Maps are powerful data structures that allow you to store and access values using unique keys. Whether you’re working in Python, Java, or JavaScript, each language provides a way to create and initialize maps with initial key-value pairs. Use them to organize and manipulate data efficiently in your programs.

#maps #programming