JS Objects: dot notation inside bracket notation, lists inside bracket notation

Question

I have an object like this:

var myob= {
title: 'Hey',
list: [3, 74, 25],
myObject: {
  myName: {
   first: "Joe",
   second: "Flynn"
}
}

I am trying to access the inner content via bracket notation.

myob["title"] //works fine, returns 'Hey'
myob["list[0]"] //Doesn't work, returns undefined
myob["myObject[objectTitle]"] //Doesn't work, returns undefined

Why doesn't this work? Is there a way I could do this, preferably still using the same content inside the brackets...?

Link to a jsfiddle: https://jsfiddle.net/j24dxpao/

Why, because it is looking for `myob = { "list[0]" : 123 }`, so no there is no way to do what you are trying to do. — epascarello, Nov 09 '17 at 14:46

score 4 · Answer 1 · answered Nov 09 '17 at 14:53

4

For these kind of string-based nested object access, you might wanna use a library like lodash's get or equivalent, as it is not natively possible.

const _ = require("lodash")
const schoolEvent = {
    guests: [
        {name: "John", handsome: true},
        {name: "Ben", handsome: false}
    ]
}

_.get(schoolEvent, "guests[0].name") // "John"

answered Nov 09 '17 at 14:53

Radioreve

3,173
3
19
32

Yes, but this is for an npm package and I don't want any dependencies – Ben Gubler Nov 09 '17 at 14:54
2

If this is the notation you dig, then implement your own get fn. Otherwise, stick with the native notation. As others have pointed out this is the only solution. The only downside is that you have to make sure that each time you go down a level, the key you're on exists. Otherwise, "undefined is not a function" will pop up – Radioreve Nov 09 '17 at 14:56

score 3 · Accepted Answer · answered Nov 09 '17 at 14:50

3

Each index has to be enclosed by it's own brackets.

To access those objects with those paths, use

myob["title"]
myob["list"][0] 
myob["myObject"]["objectTitle"]

answered Nov 09 '17 at 14:50

Jesse Schokker

896
7
19

score 0 · Answer 3 · answered Nov 09 '17 at 14:49

0

var myob= {
title: 'Hey',
list: [3, 74, 25],
myObject: {
  myName: {
   first: "Joe",
   second: "Flynn"
}
}

each key can be accessed by

myob['title']
myob['list'][0]
myob['myObject']['objectTitle']

answered Nov 09 '17 at 14:49

Pratheesh M

1,028
6
13

JS Objects: dot notation inside bracket notation, lists inside bracket notation

3 Answers3