how to add script before </body> in magento 2 code example

Example: how to add script before in magento 2

Add referenceContainer code in layout file

app/design/frontend///Magento_Theme/layout/default.xml

Before body end

 
      
    
For after body start

 
      
    
Create js.phtml template file and put your js script/code in this file.

app/design/frontend///Magento_Theme/templates/js/js.phtml