freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/accessing-nested-arrays.english.md

id, title, challengeType, videoUrl

id	title	challengeType	videoUrl
56533eb9ac21ba0edf2244cd	Accessing Nested Arrays	1	https://scrimba.com/c/cLeGDtZ

Description

As we have seen in earlier examples, objects can contain both nested objects and nested arrays. Similar to accessing nested objects, Array bracket notation can be chained to access nested arrays. Here is an example of how to access a nested array:

var ourPets = [
  {
    animalType: "cat",
    names: [
      "Meowzer",
      "Fluffy",
      "Kit-Cat"
    ]
  },
  {
    animalType: "dog",
    names: [
      "Spot",
      "Bowser",
      "Frankie"
    ]
  }
];
ourPets[0].names[1]; // "Fluffy"
ourPets[1].names[0]; // "Spot"

Instructions

Retrieve the second tree from the variable myPlants using object dot and array bracket notation.

Tests

tests:
  - text: <code>secondTree</code> should equal "pine"
    testString: assert(secondTree === "pine", '<code>secondTree</code> should equal "pine"');
  - text: Use dot and bracket notation to access <code>myPlants</code>
    testString: assert(/=\s*myPlants\[1\].list\[1\]/.test(code), 'Use dot and bracket notation to access <code>myPlants</code>');

Challenge Seed

// Setup
var myPlants = [
  {
    type: "flowers",
    list: [
      "rose",
      "tulip",
      "dandelion"
    ]
  },
  {
    type: "trees",
    list: [
      "fir",
      "pine",
      "birch"
    ]
  }
];

// Only change code below this line

var secondTree = ""; // Change this line

After Test

(function(x) {
  if(typeof x != 'undefined') {
    return "secondTree = " + x;
  }
  return "secondTree is undefined";
})(secondTree);

Solution

var myPlants = [
  {
    type: "flowers",
    list: [
      "rose",
      "tulip",
      "dandelion"
    ]
  },
  {
    type: "trees",
    list: [
      "fir",
      "pine",
      "birch"
    ]
  }
];

// Only change code below this line

var secondTree = myPlants[1].list[1];