JavaScript set object key by variable

ES6

var key = "name";
var person = {[key]:"John"};
console.log(person); // should print  Object { name="John"}

Before ES6

var person = {};
var key = "name";

person[key] /* this is same as person.name */ = "John";

console.log(person); // should print  Object { name="John"}

Give random colors to text in a page using D3

d3.selectAll("*").style("color", function() {
  return "hsl(" + Math.random() * 360 + ",100%,50%)";
});