CODEWITHSUNDEEP
javascript
maxtwoknight
maxtwoknight

Reputation: 5346

Are dashes allowed in javascript property names?

I was looking at http://docs.jquery.com/Plugins/Authoring#Defaults_and_Options to create a simple plugin for jQuery. Following the section about options and settings, I did the following, which didn't work (the script quit when it encountered the setting).

var settings = {
    'location' : 'top',
    'background-color': 'blue'
}
...
$this.css('backgroundColor', settings.background-color); // fails here

Once I removed the dash from the background color, things work properly. 

var settings = {
    'location' : 'top',
    'backgroundColor': 'blue' // dash removed here
}
...
$this.css('backgroundColor', settings.backgroundColor);

Am I missing something, or are the jQuery docs wrong?

Upvotes: 80

Views: 100817

Answers (5)

Primoz Rome
Primoz Rome

Reputation: 11031

You can do something like this:

var myObject = {
  propertyOne: 'Something',
  'property-two': 'Something two'  
}

for (const val of [
  myObject.propertyOne,
  myObject['propertyOne'],
  myObject['property-two']
  ]){
  console.log(val)
}

Upvotes: 7

JaredPar
JaredPar

Reputation: 754635

Dashes are not legal in javascript variables. A variable name must start with a letter, dollar sign or underscore and can be followed by the same or a number.

Upvotes: 6

sdleihssirhc
sdleihssirhc

Reputation: 42496

You can have dashes in strings. If you really wanted to keep that dash, you'd have to refer to the property using brackets and whatnot:

$this.css('backgroundColor', settings['background-color']);

Upvotes: 5

gen_Eric
gen_Eric

Reputation: 227230

Change settings.background-color to settings['background-color'].

Variables cannot contain - because that is read as the subtract operator.

Upvotes: 18

Daniel A. White
Daniel A. White

Reputation: 190925

no. the parser will interpret it as the subtract operator.

you can do settings['background-color'].

Upvotes: 154

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