How to Convert Iterables to Objects Using Object.fromEntries() in JavaScript

In JavaScript, managing key-value pairs is a frequent task. The Object.fromEntries() method, introduced in ECMAScript 2019, simplifies this by allowing you to easily convert an iterable (such as an array or a Map) into a plain object. This function is incredibly helpful when dealing with Map objects or transforming data structures that hold key-value pairs.

Syntax and Usage:
The syntax of the Object.fromEntries() method is straightforward:
`Object.fromEntries(iterable);

Example
const entries = [['name', 'John'], ['age', 30], ['city', 'New York']];
const obj = Object.fromEntries(entries);
console.log(obj);
Output


{ name: 'John', age: 30, city: 'New York' }

In this example, the Object.fromEntries() method converts an array of arrays (each containing a key-value pair) into an object.

Practical Applications:
Converting Maps to Objects: If you have a Map object and want to convert it into a plain object, Object.fromEntries() provides an easy solution.

const map = new Map([
['name', 'Alice'],
['age', 25]
]);

const userObj = Object.fromEntries(map);
console.log(userObj); // { name: 'Alice', age: 25 }
Filtering Key-Value Pairs: You can also use Object.fromEntries() in combination with other array methods to filter and modify key-value pairs before converting them into an object.

const data = [
['name', 'Alice'],
['age', 25],
['city', 'Paris']
];

const filteredData = Object.fromEntries(
data.filter(([key, value]) => key !== 'age')
);

console.log(filteredData); // { name: 'Alice', city: 'Paris' }
Performance Considerations:
Object.fromEntries() works well for typical use cases, such as converting a Map or an array of key-value pairs into an object. However, when dealing with extremely large datasets, performance might become a concern. In these cases, it is recommended to test and optimize your code for specific requirements.

Compatibility and Browser Support:
The Object.fromEntries() method is supported by the following browsers and environments:

Chrome 73+
Firefox 68+
Safari 12.1+
Node.js 12+
If you're targeting older browsers, consider using a polyfill to ensure compatibility.