var person = {
    name: 'John',
    age: 23
}; // "object literal syntax"

var person = {
    'name': 'John',
    'age': 23
}; // "object literal syntax"

person.birthday = "January 12"; // "dot syntax"

person['birthday'] = "January 12"; // "array syntax"

var prop = "birthday";
person[prop] = "January 12";

var prop = "birthday";
var person = {
    name: 'John',
    age: 23,
    (prop): 'January 12'
};

var k='propertyname';
object[k]="value";

var prop = "birthday";
var Person = function() {
    this.name = "Bob";
    this[prop] = "January 12";
};
var bob = new Person();