Push key value pair to map object javascript

Question

I have the following object

     {
     "timetable": {
         "MONDAY": {
             "start-end0": {},
             "start-end1": {},
             "start-end2": {},
             "start-end3": {},
             "start-end4": {}
         }
     }

i need to add "start-end5" to MONDAY. I tried to use dot operator to monday like timetable.monday.start-end5={} it says monday undefined

Amadan · Accepted Answer · 2016-10-06 05:25:54Z

8

monday is not MONDAY
Since start-end4 is not a valid identifier, obj.timetable.MONDAY.start-end5 = {} will not compile; you need to use the bracket syntax.

Thus,

obj.timetable.MONDAY["start-end5"] = {};

answered Oct 6, 2016 at 5:25

Amadan

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7 Comments

Don Jose Over a year ago

how can i add dynamically start-end5 start-end6... to my map??Is that possible?

VPK Over a year ago

@masSdev, what do you mean by dynamically? in iteration?

Don Jose Over a year ago

yes using iteration like obj.timetable.MONDAY["start-end"+count]

VPK Over a year ago

@masSdev, you can pass your value in the square brackets in your iteration. I think it should work.

Amadan Over a year ago

@masSdev: What do you mean, "like obj.timetable.MONDAY["start-end"+count]"? That's exactly what would work, so... not sure what kind of answer you're expecting. However, unless the format is set by someone beyond your control, that's a bad way to do things; a better would be for to have obj.timetable.MONDAY.startEnd as an array of objects, so you'd access each using obj.timetable.MONDAY.startEnd[5]. You can create it e.g. using Array.apply(null, {length: 5}).map(i => ({})) (in ES6).

|

Anik Islam Abhi · Accepted Answer · 2016-10-06 05:46:28Z

3

Variable name should be followed this restrictions

Blanks & Commas are not allowed.
No Special Symbols other than underscore(_) are allowed.
First Character should be alphabet or Underscore.

Try like this

var time = {
  "timetable": {
    "MONDAY": {
      "start-end0": {},
      "start-end1": {},
      "start-end2": {},
      "start-end3": {},
      "start-end4": {}
    }
  }
}

time.timetable.MONDAY["start-end5"] = {}

DEMO

Addtion:

how can i add dynamically start-end5 start-end6... to my map??Is that possible?

Ans

Add a loop and concat string according to value.

Like this

var time = {
  "timetable": {
    "MONDAY": {
      "start-end0": {},
      "start-end1": {},
      "start-end2": {},
      "start-end3": {},
      "start-end4": {}
    }
  }
}
for(var i=0;i<5;i++) // set the limit of loop according to your need
  time.timetable.MONDAY["start-end"+i] = {}

DEMO

edited Oct 6, 2016 at 5:46

answered Oct 6, 2016 at 5:27

Anik Islam Abhi

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7 Comments

Anik Islam Abhi Over a year ago

well, that's the most basic restrictions @Rayon

Don Jose Over a year ago

how can i add dynamically start-end5 start-end6... to my map??Is that possible?

Anik Islam Abhi Over a year ago

I have added my ans @masSdev

Don Jose Over a year ago

its giving monday as undefined

Anik Islam Abhi Over a year ago

check demo i have attached @masSdev

|

nikjohn · Accepted Answer · 2016-10-06 05:48:51Z

2

You need to use the [""] notation here, as your key name is not camelCase or other valid object key naming

a.timetable.MONDAY["start-end5"] = {};

edited Oct 6, 2016 at 5:48

answered Oct 6, 2016 at 5:27

nikjohn

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Comments

Jack Connor · Accepted Answer · 2016-10-06 06:05:48Z

1

One more completely viable (and very readable) syntax I'd like to add, just for fun:

time["timetable"]["MONDAY"]["start-end5"] = {};

answered Oct 6, 2016 at 6:05

Jack Connor

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