Create an object with dynamic keys

Written byPhuoc Nguyen

Tags

JavaScript

Created

25 Feb, 2021

We often use the bracket notation to add a dynamic key to an object.

const key = 'ages';
const person = {
    name: 'John Doe',
};

person[key] = 42;

ES6 allows us to do that in a declarative way as following:

const key = 'ages';
const person = {
    name: 'John Doe',
    [key]: 42,
};

Here is a simple usage. The sample code below returns the list of name and value of given input fields in a form:

// `formEle` is the form element
const data = [...formEle.querySelectorAll('input')].map((field) => {
    return {
        [field.getAttribute('name')]: field.getAttribute('value'),
    };
});

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Phước Nguyễn

Create an object with dynamic keys

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