In ES6, you can do like this.
var key = "name";
var person = {[key]:"John"}; // same as var person = {"name" : "John"}
console.log(person); // should print Object { name="John"}
var key = "name";_x000D_
var person = {[key]:"John"};_x000D_
console.log(person); // should print Object { name="John"}
_x000D_
Its called Computed Property Names, its implemented using bracket notation( square brackets) []
Example: { [variableName] : someValue }
Starting with ECMAScript 2015, the object initializer syntax also supports computed property names. That allows you to put an expression in brackets [], that will be computed and used as the property name.
For ES5, try something like this
var yourObject = {};
yourObject[yourKey] = "yourValue";
console.log(yourObject );
example:
var person = {};
var key = "name";
person[key] /* this is same as person.name */ = "John";
console.log(person); // should print Object { name="John"}
var person = {};_x000D_
var key = "name";_x000D_
_x000D_
person[key] /* this is same as person.name */ = "John";_x000D_
_x000D_
console.log(person); // should print Object { name="John"}
_x000D_