Extract only values from JSON object in javascript without using a loop

Question

is there a "Nice" way to get all the values out of a json object (I don't care about the keys) - just get the values into array, without using a loop ? (lang is Javascript)

Answer 1

It depends on how you define "loop".

You can extract the properties with Object.keys and then map them to their values.

… it's still essentially a loop under the hood though.

var json = `{ "foo": 1, "bar": 2, "baz": 3 }`;
var obj = JSON.parse(json);
var values = Object.keys(obj).map(function (key) { return obj[key]; });
console.log(values);

With weaker browser support you could use the values method.

var json = `{ "foo": 1, "bar": 2, "baz": 3 }`;
var obj = JSON.parse(json);
var values = Object.values(obj);
console.log(values);

Answer 2

I think you are looking for Object.values() function, just pass the object to the values method of Object as first param. That's it!

Object.values({something: 'lol'});
> ["lol"]

Answer 3

Recursively extract as text

Yes, this is a loop but the underlying methods you are calling such as Object.values or arr.map are still loops. I found this useful for extracting text out of a json object for full text search in particular and thought it useful as I came here initially needing this but the answers only touched the surface as json is recursive in nature.

function textFromJson(json) {
    if (json === null || json === undefined) {
      return '';
    }
    if (!Array.isArray(json) && !Object.getPrototypeOf(json).isPrototypeOf(Object)) {
      return '' + json;
    }
    const obj = {};
    for (const key of Object.keys(json)) {
        obj[key] = textFromJson(json[key]);
    }
    return Object.values(obj).join(' ');
}

Answer 4

With ES2017 you have Object.values(). You can polyfill it also.

Only you need is transform JSON to JavaScript object and call Object.values(). The result is an array of values.

var obj = JSON.parse(jsonData);
var result = Object.values(obj);