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JavaScript – Convert Two-Dimensional Array Into an Object

Last Updated : 11 Jan, 2025
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Here are the different methods to convert the two-dimensional array into an object in JavaScript.

1. Using a for Loop

The simplest way to convert a two-dimensional array into an object is by iterating through the array using a for loop and assigning key-value pairs.

JavaScript
const a = [['name', 'Abhay'], ['age', 30], ['city', 'New Delhi']];

const obj = {};
for (let i = 0; i < a.length; i++) {
    const [key, val] = a[i];
    obj[key] = val;
}
console.log(obj);

Output
{ name: 'Abhay', age: 30, city: 'New Delhi' }

In this example

  • The for loop iterates through the two-dimensional array a, destructuring each sub-array into a key and val, and assigns these as key-value pairs to the obj, effectively converting the array into an object.

2. Using reduce() Method

The reduce() method provides a clean, concise way to transform a two-dimensional array into an object in a single operation.

JavaScript
const a = [['name', 'Jaya'], ['age', 30], ['city', 'New Delhi']];

const obj = a.reduce((acc, [key, val]) => {
    acc[key] = val;
    return acc;
}, {});

console.log(obj);

Output
{ name: 'Jaya', age: 30, city: 'New Delhi' }

In this example

  • The reduce() method processes each sub-array in a, destructuring it into key and val, and adds them as properties to the acc object.
  • The final accumulated object, obj, contains all key-value pairs from the two-dimensional array.

3. Using Object.fromEntries()

With the introduction of Object.fromEntries() in ES2019, converting a two-dimensional array into an object has become straightforward and efficient.

JavaScript
const a = [['name', 'Joy'],['age', 30],['city', 'New Delhi']];
const obj = Object.fromEntries(a);
console.log(obj);

Output
{ name: 'Joy', age: 30, city: 'New Delhi' }

In this example :

  • The Object.fromEntries() method directly converts the two-dimensional array a into an object by treating each sub-array as a [key, value] pair.
  • The resulting object, obj, contains the key-value pairs extracted from the array.

Comparison and Use Cases

ApproachWhen to Use

for loop

Basic and widely supported, useful for beginners.
reduceWhen functional programming style is preferred.
Object.fromEntries()For modern JavaScript, concise, and easy to read.

By selecting the appropriate approach, you can effectively convert a two-dimensional array into an object based on your requirements.


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