Javascript is a programming or scripting language primarily used for client-sided programming in web browsers. It can also be used as a server-side programming language but this is generally used less often. Javascript was originally created by Netscape for their browser Netscape Navigator, and is now an implementation of the ECMAScript standard. It is typically used in web browsers for form validation, floating navigation, AJAX and other nifty things to make web pages more interactive.
There may be times when you need to know the index of the element that is clicked from within a group of elements e.g. a group of divs inside another div. This can be done easily with jQuery using the index() function.
The Javascript Math object has various mathematical functions and constants including .round() for rounding, ceil() for rounding numbers up and floor() for rounding numbers down.
The value of an HTML file input field cannot be changed or reset (without doing a full form reset) for security reasons. The other day I read Bogdan Gusiev’s post about how to clear an upload file input field by resetting the HTML of a containing div to its intial state using Javascript and thought I’d take it one step further by doing this in jQuery and adding a clear button next to any file input field on a web page.
This post shows a simple way to make anchor tags with e.g. href="#top" scroll to the top of the webpage when clicked using jQuery.
Earlier today I posted how to loop through elements in jQuery but as pointed out by Bloid at DZone it wasn’t a very good way of doing it. This post is a revision to that earlier post and thanks to Bloid for letting me know a much better (and more jQuery way) of doing this.
If you need to measure how long something takes with Javascript you can use the Date() object to get a start timestamp and then compare it later on using a second Date() object. Although I’m sure there are other benchmarking plugins etc available this can be a quick and easy way to benchmark something in Javascript.