freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-data-structures/modify-an-object-nested-within-an-object.english.md

id, title, challengeType, forumTopicId

id	title	challengeType	forumTopicId
587d7b7c367417b2b2512b19	Modify an Object Nested Within an Object	1	301164

Description

Now let's take a look at a slightly more complex object. Object properties can be nested to an arbitrary depth, and their values can be any type of data supported by JavaScript, including arrays and even other objects. Consider the following:

let nestedObject = {
  id: 28802695164,
  date: 'December 31, 2016',
  data: {
    totalUsers: 99,
    online: 80,
    onlineStatus: {
      active: 67,
      away: 13
    }
  }
};

nestedObject has three unique keys: id, whose value is a number, date whose value is a string, and data, whose value is an object which has yet another object nested within it. While structures can quickly become complex, we can still use the same notations to access the information we need.

Instructions

Here we've defined an object, userActivity, which includes another object nested within it. You can modify properties on this nested object in the same way you modified properties in the last challenge. Set the value of the online key to 45.

Tests

tests:
  - text: <code>userActivity</code> should have <code>id</code>, <code>date</code> and <code>data</code> properties.
    testString: assert('id' in userActivity && 'date' in userActivity && 'data' in userActivity);
  - text: <code>userActivity</code> should have a <code>data</code> key set to an object with keys <code>totalUsers</code> and <code>online</code>.
    testString: assert('totalUsers' in userActivity.data && 'online' in userActivity.data);
  - text: The <code>online</code> property nested in the <code>data</code> key of <code>userActivity</code> should be set to <code>45</code>
    testString: assert(userActivity.data.online === 45);
  - text: The <code>online</code> property should be set using dot or bracket notation.
    testString: 'assert.strictEqual(code.search(/online: 45/), -1);'

Challenge Seed

let userActivity = {
  id: 23894201352,
  date: 'January 1, 2017',
  data: {
    totalUsers: 51,
    online: 42
  }
};

// Only change code below this line

// Only change code above this line

console.log(userActivity);

Solution

let userActivity = {
  id: 23894201352,
  date: 'January 1, 2017',
  data: {
    totalUsers: 51,
    online: 42
  }
};

userActivity.data.online = 45;