Are dashes allowed in javascript property names?

Question

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?

Answer 1

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

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

Answer 2

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

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

Answer 3

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.

Answer 4

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) }

Answer 5

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']);