JavaScript Objects

Object.keys(obj) returns an array of keys in a hash object.

Examples:

var arr = ['a', 'b', 'c'];
console.log(Object.keys(arr)); // console: ['0', '1', '2']

// array like object
var obj = { 0: 'a', 1: 'b', 2: 'c' };
console.log(Object.keys(obj)); // console: ['0', '1', '2']

// array like object with random key ordering
var an_obj = { 100: 'a', 2: 'b', 7: 'c' };
console.log(Object.keys(an_obj)); // console: ['2', '7', '100']

Object.values(obj) returns an array of values in a hash object.

Examples:

var obj = { foo: 'bar', baz: 42 };
console.log(Object.values(obj)); // ['bar', 42]

// array like object
var obj = { 0: 'a', 1: 'b', 2: 'c' };
console.log(Object.values(obj)); // ['a', 'b', 'c']

// array like object with random key ordering
var an_obj = { 100: 'a', 2: 'b', 7: 'c' };
console.log(Object.values(an_obj)); // ['b', 'c', 'a']

obj.hasOwnProperty(prop) returns true/false indicating if an object has the specified property (key, NOT value).

Examples:

var object = {cat: 'meow'};
object.hasOwnProperty('cat'); // true
object.hasOwnProperty('meow'); // false

To access a property’s value:  object[key]

Example:  object['cat']; // 'meow'

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JavaScript Objects

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