How do I declare a function async in a JavaScript object literal/initialiser?

Question

I'd like to have the loadConfig function async and just finish after the resource has been loaded. await fetchetc. How can I declare it in this object syntax as an async function?

var QMEM = QMEM || { config : null, loadConfig : function(url) { console.log('url = ', url); fetch(url) .then(res => res.json()) .then(out => { this.config = out; }) .catch(err => console.log(err)); }, logConfig : function() { console.log('current configuration:\n', this.config); } }; QMEM.loadConfig(myConfigUrl); QMEM.logConfig();

Put the keyword async before function? Is that what you're asking? — Pointy
– Pointy, Commented Jul 9 at 15:23
Tried that, gave me a "bad invocation error, expected function or {" — rhavin
– rhavin, Commented Jul 9 at 15:24
@rhavin does the environment you're running this JS code in support async operations? Also note that this in the final then call will not be a reference to the outer object. You'll need to amend the scope — Rory McCrossan
– Rory McCrossan, Commented Jul 9 at 15:29
Don't confuse object initializers (which are part of JavaScript) with JavaScript Object Notation (which is a data format based on a subset of JavaScript). — Quentin
– Quentin, Commented Jul 9 at 15:34

3 revs, 2 users 86% · Accepted Answer · 2025-07-09 15:59:36Z

It isn't relevant that you are assigning the function as a value of a property in an object initilizer.

You mark it as asynchronous in the same way that you mark any function expression:

async function() { // function body }

So:

loadConfig : async function(url) {

Or using shorthand method notation:

async loadConfig(url) {

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