19_generatArrayOfObjectKeys.js

/* Generate an Array of All Object Keys with 
Object.keys() */

const oldUsers = {
    Alan: {
        online: false
    },
    Jeff: {
        online: true
    },
    Sarah: {
        online: false
    }
};

// Object.keys() method generates an array of object keys.
console.log(Object.keys(oldUsers));  // ['Alan', 'Jeff', 'Sarah']

/* Finish writing the getArrayOfUsers function so that it
returns an array containing all the properties in the object it
receives as an argument. */

let users = {
    Alan: {
        age: 27,
        online: false
    },
    Jeff: {
        age: 32,
        online: true
    },
    Sarah: {
        age: 48,
        online: false
    },
    Ryan: {
        age: 19,
        online: true
    }
};

function getArrayOfUsers(obj) {
    // Only change code below this line
    return Object.keys(obj);
    // Only change code above this line
}

console.log(getArrayOfUsers(users));