Functional Programming - Use the map Method to Extract Data from an Array

[nicknft11]

I don’t understand what goes into maps. I am pretty lost. Why is there an arrow, and is user a new variable? It would be a big help if someone could explain what to put into maps.

*Your code so far

const users = [
  { name: 'John', age: 34 },
  { name: 'Amy', age: 20 },
  { name: 'camperCat', age: 10 }
];

const names = users.map(user => user.name);
console.log(names);

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Challenge: Functional Programming - Use the map Method to Extract Data from an Array

Link to the challenge:

freeCodeCamp.org

[JeremyLT]

The arrow is a different way to write a function

freeCodeCamp.org

Map takes as its argument a function that accepts an array element as the input and returns the corresponding element for the new array.

[nicknft11]

Ok, I came up with this but it still doesn’t work. Wouldn’t map look at each object in the watchList and create a new object with title and ratings then put all the new objects in an array? Edit: the solution has 1 more parenthesis around the object. If I do that then it works. What is the need for the extra parenthesis?

const ratings = watchList.map(movie => {title: movie["Title"], rating: movie["imdbRating"]});

[JeremyLT]

You need to do something extra to return an object from an arrow function. I’m not at my desk, but I’d Google “arrow function return object mdn”