Re-using options variable as output for jquery extend

Question

Normally when you extend it options with defaultOptions you create a new object, but I would like to re-use the options object. See below code.

I basically want to do the following:

var defaultOptions = {'width': '10px', 'size': '10px'};

var options = {'width': '300px', 'name': 'sam'};

// I want to re-use the same options variable as target for extend
var optionsAfterExtend = $.extend(options, defaultOptions, options);

// should return true
alert(options.width == '300px');
alert(optionsAfterExtend == '300px');
alert(options.size == '10px');
alert(optionsAfterExtend == options);

// Because I may add extra info to the options object which the client using my plugin can use / re-use
optionsAfterExtend.data = 'sam';

// So now optionsAfterExtend.data and options.data should both equal 'sam'

Tried searching for a long time and read the jquery extend documentation, but couldn't find a proper way to do it. Is it just stupid that I want this? Even if so I'm still curious how to do it in a nice way.

If you do optionsAfterExtend.data = 'sam'; there is no way that optionsAfterExtend.data == optionsAfterExtend will return true, because your checking if the value of a property is the same as the object itself. — Johannes Klauß
– Johannes Klauß, Commented Mar 19, 2013 at 13:51
Updating the question, thats incorrect wording of my question. I will also try to make the question clearer. Sorry for the confusion — Sam Stoelinga
– Sam Stoelinga, Commented Mar 19, 2013 at 13:52
Are you asking how to update options every time optionsAfterExtend is changed? — Jeff Shaver
– Jeff Shaver, Commented Mar 19, 2013 at 13:56
Yea kind of, I would like to have options and optionsAfterExtend to point to the same object, so basically instead of creating a new object, I would like to have the extend merge the properties back into the orignal options object. — Sam Stoelinga
– Sam Stoelinga, Commented Mar 19, 2013 at 13:58

Guffa · Accepted Answer · 2013-03-19 14:00:37Z

3

The extend method copied all properties into the object that you send in as the first parameter. To create a new object that is a combination of the others, supply an empty object as the first parameter:

var optionsAfterExtend = $.extend({}, defaultOptions, options);

If you also want the options object to change, and the objects to be the same, make a new object and then extend it back to options:

var o = $.extend({}, defaultOptions, options);
var optionsAfterExtend = $.extend(options, o);

edited Mar 19, 2013 at 14:00

answered Mar 19, 2013 at 13:53

Guffa

703k112 gold badges760 silver badges1k bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Re-using options variable as output for jquery extend

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related