Convert object to array in Javascript / React

Question

Using REST, I am retrieving an object(JSON format) which is to be converted to an array so that it can be inserted into a table.

This is done in the rendering function of React.

The input is updated every N minutes from the back-end.

How do I convert an object to an array?

I need only the values, not the keys, since the keys are already present as column values beforehand in the table itself.

Answer 1

You can use Object#values (ECMAScript 2017), but it's not supported by IE (see browser's compatibility).

Note: The ECMAScript 6 specification defines in which order the properties of an object should be traversed. This blog post explains the details.

const map = { a: 1, b: 2, c: 3 };

const result = Object.values(map);

console.log(result);

If you need to support IE, you can use Object#keys with Array#map:

const map = { a: 1, b: 2, c: 3 };

const result = Object.keys(map).map((key) => map[key]);

console.log(result);

Answer 2

I am not sure by map you mean the Map object or an ordinary JS object. However, just for variety I would like to mention that the Map objects are mostly (probably always) stringified like JSON.stringify([...myMap]). So if you happen to receive a Map object in JSON data may be you should do something like;

var myMap = new Map().set(1,"hey").set(2,"you"),
  mapData = JSON.stringify([...myMap]),
   values = JSON.parse(mapData).map(d => d[1]);
console.log("mapData:",mapData);
console.log("values:",values);