javascript - Read For Learn

Preloading images with jQuery

Quick and easy: Or, if you want a jQuery plugin:

lodash multi-column sortBy

There’s a nifty method to sort an array of objects based on several properties: However that is only for ascending sorting. Is there some handy way of defining direction per column? E.g.

Complex JSON nesting of objects and arrays

The first code is an example of Javascript code, which is similar, however not JSON. JSON would not have 1) comments and 2) the var keyword You don’t have any comments in your JSON, but you should remove the var and start like this: The [{}] notation means “object in an array” and is not … Read more

How to get the browser viewport dimensions?

I want to provide my visitors the ability to see images in high quality, is there any way I can detect the window size? Or better yet, the viewport size of the browser with JavaScript? See green area here:

getContext is not a function

Your value: is a jQuery object, not a pure Canvas element. To turn it back so you can call getContext(), call this.element.get(0), or better yet store the real element and not the jQuery object: See running code at http://jsfiddle.net/alnitak/zbaMh/, ideally using the Chrome Javascript Console so you can see the resulting object in the debug … Read more

One liner to flatten nested object

Here you go: Summary: recursively create an array of one-property objects, then combine them all with Object.assign. This uses ES6 features including Object.assign or the spread operator, but it should be easy enough to rewrite not to require them. For those who don’t care about the one-line craziness and would prefer to be able to … Read more

How do I know which version of Javascript I’m using?

Wikipedia (or rather, the community on Wikipedia) keeps a pretty good up-to-date list here. Most browsers are on 1.5 (though they have features of later versions) Mozilla progresses with every dot release (they maintain the standard so that’s not surprising) Firefox 4 is on JavaScript 1.8.5 The other big off-the-beaten-path one is IE9 – it … Read more