How to set data-target dynamically in javascript

1. How to use data toggle in JavaScript?
2. What is data-target JavaScript?

How to use data toggle in JavaScript?

Just add data-toggle="collapse" and a data-target to element to automatically assign control of a collapsible element. The data-target attribute accepts a CSS selector to apply the collapse to. Be sure to add the class collapse to the collapsible element. If you'd like it to default open, add the additional class in.

What is data-target JavaScript?

data-target is used by bootstrap to make your life easier. You (mostly) do not need to write a single line of Javascript to use their pre-made JavaScript components. The data-target attribute should contain a CSS selector that points to the HTML Element that will be changed. Modal Example Code from BS3: <!--