JavaScript - Convert Two-Dimensional Array Into an Object

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.

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);

{ 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.

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

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

console.log(obj);

{ 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.

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

{ 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

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