const object = {1: 'a', 2: 'b', 3: 'c'};

​

// convert to the array keys 

let array =Object.keys(object);

​

// index is based on zero

let newArray = array.map((item, index) => {

    console.log(`Item => "${item}", Index => ${index}`);

    return item * 2;

});

​

// newArray will be [2, 4, 6]

const object = {1: 'a', 2: 'b', 3: 'c'};

​

// convert to the array keys 

let array =Object.keys(object);

​

// index is based on zero

let newArray = array.map((item, index) => {

    console.log(`Item => "${item}", Index => ${index}`);

    return item * 2;

});

​

// newArray will be [2, 4, 6]

// simple array

const arr = ['a', 'b', 'c'];

console.log(Object.keys(arr)); // console: ['0', '1', '2']

​

// array-like object

const obj = { 0: 'a', 1: 'b', 2: 'c' };

console.log(Object.keys(obj)); // console: ['0', '1', '2']

​

// array-like object with random key ordering

const anObj = { 100: 'a', 2: 'b', 7: 'c' };

console.log(Object.keys(anObj)); // console: ['2', '7', '100']

​

// getFoo is a property which isn't enumerable

const myObj = Object.create({}, {

  getFoo: {

    value: function () { return this.foo; }

  }

});

myObj.foo = 1;

console.log(Object.keys(myObj)); // console: ['foo']

const object = {'a': 1,'b': 2, 'c': 3};

​

// convert to the array keys 

let array = Object.keys(object);

​

console.log(array);

// => ['a', 'b', 'c']

​

let newArray = array.map(item => return item + '-X' )

​

console.log(newArray);

// => ['a-X', 'b-X', 'c-X']

​

const object = {1: 'a', 2: 'b', 3: 'c'};

​

// convert to the array keys 

let array =Object.keys(object);

​

let newArray = array.map((item, index) => {

    return item * 2;

});

​

// newArray will be [2, 4, 6]