Do I use .size() or .length in Javascript?
Share
Do I use .size() or .length in Javascript?
Let’s have a closer look…
.size() simply calls .length (clearly shown this in the jQuery source code below) so we are saving a function call
//https://code.jquery.com/jquery-latest.js
// The number of elements contained in the matched element set
size: function() {
return this.length;
},
.length() has been proved to be faster than .size() (clearly shown is a jsperf http://jsperf.com/size-vs-length test). So why is the .size() function in jQuery? My initial guess would be that they are keeping it abstract so that if a different way of calculating the .length is required in the future it may provide a backwards compatible API.
Common usage you may have seen:
//check if a DOM element is present
if ($('#id').length > 0) { ... }
So in a nutshell, I use .length until someone gives me a substantial reason not to.