Find a value within a nested array

JavaScript
1

Hey can anyone see what I’m doing wrong here?

function locateEntertainmentFansByType(activitiesObj, activityType) {
  const enthusiastsArr = [];

  const activityEntriesArr = Object.entries(activitiesObj);

  activityEntriesArr.forEach(entry => {
    if (entry[1].includes(activityType)) {
      enthusiastsArr.push(entry[0]);
    }
  });

  return enthusiastsArr;
}

var activitiesObj = {
  Jack: ["Guitar", "Hiking", "Cycling"],
  Lisa: ["Pilates", "Dancing", "Reading"],
  Tom: ["Painting", "Drawing", "Hiking"]
};

console.log(locateEntertainmentFansByType(activitiesObj, "Cycling"));

Output should be John, but I get an array “1:John, 2:Adam, 3:Mary”

2

oh, Object.entries will only return keys… not sure whether I should be using Array.from instead?

3

You’re not doing anything to the result of that expression. Did you mean to do something with it? You will need to do that and use it in some way.

4

It returns an array of arrays where the first value is the key, and the second is the value of that prop in the object.

5

I think a lot of your confusion is a result of not knowing what Object.entries actually does,. and your choice of variable names.

6

in reply to steffan’s first comment: I’m adding the object to a new array?

7

The use of Object.entries is correct, there’s just an if check missing somewhere, see if you can find where it belongs.

8

What object are you talking about?

9

The correct way would be to use:

hobbiesArray.forEach(([name, hobbies]) => {


});
10

It is already used correctly, I tried the code with the if check in place and it worked.

11

Working !== right.

Objective is to be a better programmer.

1 Like
12 
function locateEntertainmentFansByType(activities, activityType) {
  const enthusiasts = [];

  const activitiesArray = Object.entries(activities);

  activitiesArray.forEach(activity => {
    if (activity[1].includes(activityType)) {
      enthusiasts.push(activity[0]);
    }
  });

  return enthusiasts;
}

var activitiesObj = {
  Jack: ["Guitar", "Hiking", "Cycling"],
  Lisa: ["Pilates", "Dancing", "Reading"],
  Tom: ["Painting", "Drawing", "Hiking"]
};

console.log(locateEntertainmentFansByType(activitiesObj, "Hiking"));

it worked! thanks Steffan!

2 Likes
13

Applying what @kerafyrm02 said (using array destructuring), that part would look like this:

hobbiesArray.forEach(([name, hobbies]) => {
    if (hobbies.includes(hobby)) {
      newArray.push(name);
    }
  });

Indeed, much more readable.

14

Readability of code is probably one of the most important qualities a programmer can have.

1 Like