What do curly braces inside of function parameter lists do in es6?
It is destructuring, but contained within the parameters. The equivalent without the destructuring would be:
const func = o => {
var param1 = o.param1;
var param2 = o.param2;
//do stuff
}
This is passing an object as a property.
It is basically shorthand for
let param1 = someObject.param1
let param2 = someObject.param2
Another way of using this technique without parameters is the following, let's consider then for a second that someObject does contain those properties.
let {param1, param2} = someObject;