freeCodeCamp Challenge Guide: Use the map Method to Extract Data from an Array

Guide
1

Use the map Method to Extract Data from an Array

Hints

Hint 1

array.prototype.map takes a function as in input and returns an array. The returned array includes elements that is processed by the function. This function takes individual elements as input.

Solutions

Solution 1 (Click to Show/Hide) 
const ratings = watchList.map(item => ({
  title: item["Title"],
  rating: item["imdbRating"]
}));

Code Explanation

Using ES6 notation, each item in array is processed to extract title and rating.
Parantheses are needed to return an object.

Solution 2 (Click to Show/Hide) 
const ratings = watchList.map(({ Title: title, imdbRating: rating }) => ({title, rating}));

Code Explanation

Using parameter destructuring, the title and rating are extracted and returned in an object. Parantheses are needed to return an object.

Relevant Links

107 Likes
2

Hello campers,here is how i did it:

var oldArray = [1,2,3,4,5];

// Only change code below this line.

var newArray = oldArray.map(function(val) {
return val + 3;
});

console.log(oldArray);
console.log(newArray);

13 Likes
3

Hey this should work but it is not passing all tests!

var oldArray = [1,2,3,4,5];

// Only change code below this line.
var newArray = Array.prototype.map.call(oldArray,function(i,v){
return i+3;
});

2 Likes