Before we look at some examples here some Important things that you need to know about JS Link Property.
1. JS link is a new SPField Type property that not only lets you Control the Rendering of a Field or Control in a List, but also Rendering of a List Item,Content type,Form,View and a List view web part Instance.
2. Rendering of Fields can be Controlled in NewForm.aspx, DisplayForm.aspx and EditForm.aspx forms.
3. JS Link Override will not work if you are using the Custom List Form (i.e. it is edited in SharePoint Designer).
Lets look at some examples-
Add Task Status Indicators in SharePoint 2013 using JS Link – This is an Example of Overriding Status Column in a View using JS Link.
Customize List Form Fields in Display Form (DispForm.aspx) using JS Link in SharePoint 2013 – Example of how to apply JS Link in DisplayForm.aspx ListForm.
Customize Fields in NewForm.aspx (Hide,Disable,Pre-Populate) with JS Link in SharePoint 2013 – SharePoint 2013 JS Link example where we will look at how to Hide,Disable and Pre-Populate Fields in NewForm.aspx.
Original article : Here