Shorthand for empty function in Node.js

Question

In JS, there is shorthand for an empty object which is {}. Is there shorthand for an empty function in JS?

The reason being, as functions are first-class objects, we use them as arguments more often, but passing in an empty function is at best ugly.

var foo = baz(function(){}); 

In order to declare a function, at somepoint we have to declare function(){}.

I would like more Node.js APIs to require a (callback) function to be passed, so the API doesn't deceivingly look synchronous. Perhaps one step in that direction would be to create shorthand for empty placeholder functions.

Answer 1

No, there is not. With ES6, you might be able to use an arrow function: ()=>{} which is a bit shorter.

If you really need this very often (you shouldn't?!), you can declare one yourself:

function noop(){} 

and then refer to that repeatedly. If you don't want to clutter your scope, you can also use the Function.prototype function (sic!) which does nothing but constantly return undefined - yet that's actually longer than your function expression.

Answer 2

ES6 one could be:

   const noop = () => {}; 

Be careful if using Babel as it compiles differently - instead you can explicitly return something:

   const noop = () => ({}); 

See this tweet as to why the curly braces are important: https://twitter.com/_ericelliott/status/601420050327711744?lang=en