Traversing Arrays by forEach

January 14, 2022

Trying to traverse an array into an object with key/pair (yes I know of reduce):

This is the array:

filtered2 = [["deviceName", "TestDevice00003"], ["hwModelName", "TestHwModel03"], ["deviceTypeName", "TestDeviceType03"], ["serviceTag", "A1A03"]]

But for some reason when I do forEach:

filtered2.forEach( (indiv) => {
  console.log([indiv[0]]+" | " +[indiv[1]])
    obj3 = {
      ...obj3,
      [[indiv[0]][0]]  : [indiv[1]]
    }
})

Console.log will see each (indiv) as "hwModelName | TestHwModel03"
at [indiv[0]]+" | " +[indiv[1]], so both are basic strings

But the forEach function sees [indiv[1]] as Array ["TestHwModel03"]
So I have to go one more depth level [indiv[1]][0] into the array to get the unwrapped string "TestHwModel03"

Why there this difference?

>Solution :

Remove the square brackets surrounding the value.

filtered2 = [["deviceName", "TestDevice00003"], ["hwModelName", "TestHwModel03"], ["deviceTypeName", "TestDeviceType03"], ["serviceTag", "A1A03"]]

let obj3 = {}

filtered2.forEach( (indiv) => {
    obj3 = {
      ...obj3,
      [[indiv[0]][0]]  : indiv[1]
    }
})

console.log(obj3)

Although it’s much simpler to use Object.fromEntries:

filtered2 = [["deviceName", "TestDevice00003"], ["hwModelName", "TestHwModel03"], ["deviceTypeName", "TestDeviceType03"], ["serviceTag", "A1A03"]]

let obj3 = Object.fromEntries(filtered2)
console.log(obj3)