indexOf() on array of objects returning why

Coding Help
1

I have an array that looks something like this:

var files = [
  {
    dir: '/home/runner/random-stuff',
    file: '03:39:36 @ Aug 24, 2020-turnover-log'
  },
  {
    dir: '/home/runner/random-stuff',
    file: '04:37:02 @ Sep 12, 2020-turnover-log'
  },
  {
    dir: '/home/runner/random-stuff',
    file: '04:52:08 @ Sep 12, 2020-turnover-log.txt'
  },
  {
    dir: '/home/runner/random-stuff',
    file: '21:23:23 @ Aug 21, 2020-turnover-log'
  },
  { dir: '/home/runner/random-stuff', file: 'current-log.txt' }
]

Evidently it’s an array of objects. I tried running this code:

files.indexOf({
    dir: '/home/runner/random-stuff',
    file: '03:39:36 @ Aug 24, 2020-turnover-log'
  })

>>> -1

Why does this happen?

2

Note: I’ve already solved the problem:

files.map(x => x.file).indexOf("current-log.txt")

For some reason,

files.findIndex(x => {
x.file == "current-log.txt"
})

doesn’t work. Why don’t these two methods work?

3

The above code doesn’t works because your anonymous func inside findIndex method is returning undefined, which is equivalent to false in JS.

Try the following,

files.findIndex(obj => obj.file == 'current-log.txt')
1 Like
4

This one will never work. It is because == operator compares two objects by their address/reference, not by their value.

2 Likes