Create javascript object using constants with dots as property

Question

I have an object holding some of my program constants so that I can use it in all of the source code files. The constants object is something like this:

CONSTANTS = {
  THING_TYPE: 'type',
  THING_INFORMATION: 'information',
  THING_DESCRIPTION: 'description',
  THING_NAME: 'name',
  manyOtherConstants
}

And I want to create objects using a similar notation and using the value of the constants as a property of the object; this is what I'm trying to do:

var myObject = {
  CONSTANTS.THING_TYPE: 'whateverType',
  CONSTANTS.THING_INFORMATION: {
    CONSTANTS.THING_DESCRIPTION: 'whateverDescription',
    CONSTANTS.THING_NAME: 'whateverName',
  }
}

The problem is that I cannot use the constants in that way. Javascript says:

'SyntaxError: missing : after property id'

Is there any way of doing what I am trying to do using that notation? Or is the only thing that I can do is the following?

var myObject = {}
myObject[CONSTANTS.THING_TYPE] = 'whateverType';
myObject[CONSTANTS.THING_INFORMATION] = {};
myObject[CONSTANTS.THING_INFORMATION][CONSTANTS.THING_DESCRIPTION] = 'whateverDescription';
myObject[CONSTANTS.THING_INFORMATION][CONSTANTS.THING_NAME] = 'whateverName';

So, without using `eval` I think you could go with building an object string the way you want (1st paragraph) and then `JSON.parse` it. — Sebas, Jul 23 '14 at 22:58

score 1 · Accepted Answer · answered Jul 23 '14 at 22:58

1

No you cannot do that using object literal initialization syntax.

So the only way is to use what you do in the second case - using [...] notatin.

answered Jul 23 '14 at 22:58

zerkms

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Coming in ECMAScript 6 though. `{[CONSTANTS.THING_TYPE]: 'whateverType'}` – cookie monster Jul 23 '14 at 23:18
1

@cookie monster: that's interesting actually! But at first glance looks like using an array as a hash table key (which is valid in some languages/implementations) – zerkms Jul 23 '14 at 23:18
Ok thanks. @cookiemonster that would be grat, waiting for it. – sergioFC Jul 23 '14 at 23:28

Create javascript object using constants with dots as property

1 Answers1