Curly braces inside JavaScript arguments for functions

Question

What do the curly braces surrounding JavaScript arguments for functions do?

var port = chrome.extension.connect({name: "testing"});
port.postMessage         


        

Answer 1

var x = {title: 'the title'};

defines an object literal that has properties on it. you can do

x.title 

which will evaluate to 'the title;

this is a common technique for passing configurations to methods, which is what is going on here.