JS3 Challenge Reviews

1.js Array of values

const selectedArr = arr.filter((e,i) => {
  if(obj[e]){
    return obj[e]
  }
})
return selectedArr.map((e,i) => {
    return obj[e]
})

• Answer

const keys = Object.keys(obj)
arr.forEach((element) => {
  if (keys.includes(element)) {
    result.push(obj[element])
  }
})

return result

keys.includes(element) -> we didn't learn this, and we don't need it, and its slow. Just use the basic object knowledge, why make it so complicated?:

if (keys[element])

const solution = (num, ind = 0, arr = []) => {
  if (num === ind) {
    return arr;
  }
  arr.push(ind);
  return solution(num, ind + 1, arr);
};

• Comment

forEach is not descriptive enough, so your code is not as clear as it could be. You want to use reduce.

2.js - Create 2D array of objects

• Comment

3.js - Function from array of strings

Solution1

const solution = (arr) => {
  return (obj) => {
    const keys = Object.keys(obj)
    return arr.reduce((acc, x) => {
      if (keys.includes(x)) {
        acc[x] = obj[x]
      }
      return acc
    }, {})
  }
}

• Comment

return (obj, result={}) => {
    arr.forEach((e) => {
      if (obj[e] === undefined) return
      result[e] = obj[e]
    })
    return result
  }

• Comment