Printing all properties in a Javascript Object

I am following a code academy tutorial and i am finding this difficult.

The assignment is the following:

Use a for-in loop to print out all the properties of nyc.

var nyc = {
    fullName: "New York City",

    mayor: "Michael Bloomberg",
    population: 8000000,
    boroughs: 5
};

// write your for-in loop here
for (var  in nyc){
    console.log(population);
}