How to use a Map Data Structure In Javascript
In this approach, we’ll utilize the Map data structure to efficiently store objects by their id as keys. This allows for fast retrieval of objects by id without the need for iteration over the array.
Example: In this example we creates a map from object IDs to objects, then retrieves an object by ID and prints a specified property.
// Define an array of objects
let data = [
{ id: 1, name: "a" },
{ id: 2, name: "b" },
{ id: 3, name: "c" },
{ id: 4, name: "d" },
{ id: 5, name: "e" },
{ id: 6, name: "f" },
];
// Create a Map to store objects by their id
let map = new Map();
data.forEach(obj => map.set(obj.id, obj));
// Specify the id you want to retrieve
let idYouWant = 2;
// Retrieve the object by id from the Map
let desiredObject = map.get(idYouWant);
// Specify the property you want to print
let propertyYouWant = "name";
// Print the desired property of the retrieved object
console.log(desiredObject[propertyYouWant]); // Output: b
Output
b
How to print object by id in an array of objects in JavaScript ?
Printing an object by ID in an array of objects in JavaScript involves accessing and displaying the object that matches a specific ID value. This process typically requires iterating through the array and comparing each object’s ID property until a match is found.
There are many approaches to printing objects by id in an array of objects in JavaScript:
Table of Content
- Method 1: Using Array.filter() Method
- Method 2: Using Array.find() Method
- Method 3: Using for loop
- Method 4: Using Underscore.js _.find() Function
- Method 5: Using a Map Data Structure
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