I am going to talk about how to make those progress bar we see everyday in many applications with % completion. For example, if you're installing any app, it displays % completion of the installation while you're waiting. It is a great idea for user experience and nowadays almost every application has that kind of progress bar in it.
Let's start with simple html first.
In the HTML code that's all we need. Simple two div elements with 2 different ids. We need those div one inside another to create a simple bar through CSS styles. The parent div is the one with id=myProgress and the child div is the one with id=myBar.
Let's take a look at the CSS styles.
We are adding 100% width to the parent div id and 15% width to the child div id, which will indicate 15% progress out of 100. The child has height so the parent will be adjusted by that much height. All other properties are not required but to make it look nice, I have added those properties. For example, line-height sets the height for the line. Without that property the font won't have enough space on top of it. (We can use padding instead of it, it's up to you guys)
After that's set, we just need to make a function which will increase the width of the child and reaches to 100%.
Let's take a look at the JS code.
As I've just mentioned we needed to add a function in which it'll increase the width of child div from 15% to 100%.
For that I am getting the current value of child div with getElementById into elem. We have another variable width with 15 as value because we have the size of the child div, 15%. You can start that from 5% but it makes sense to start the progress from where it was left.
Syntax for setInterval():
setInterval(function name, time in milliseconds, parameter1, parameter2, ...)
setInterval() takes function and time as inputs and they both are required. We have given those 2 inputs as frame and 10.
That's it. You can go ahead and attach this to any web application to show the progress of any installation. It will be a nice user experience too to have on your website.
If you don't want to show the texts inside the progress bar, this is the code for that.