Parameter names with ES6?

Question

I have defined a function like:

function call_api(url, callback, query = {}, body = {})

I expected a syntax where I can provide body and skip query:

call_api('/api/clients/new', function(x){console.log(x)}, body={1:2})

But I have to use this workaround:

call_api('/api/clients/new', function(x){console.log(x)}, {}, {1:2})

Even if I provide body=, it appears its appearing as the query parameter. I use Babel with Webpack. I tried the syntax in Chrome console and in Webpack source.

Is such a syntax supported by ES6? How does it work?

Answer 1

I recommend that you work around this with passing an object and using destructuring for objects:

function callApi({url, callback, query = {}, body = {}})

And then call it as:

callAPI({url: "/api/..", callback: (x => console.log(x)), body: {a:2}})

Which would give you syntax similar to the one you want.

Named arguments have been considered and rejected for JavaScript, unlike other languages like C# and Python which sport them. Here is a recent discussion about it from the language mailing list.