bootstrap 4 need to specify col-12 code example

Example: bootstrap grid

This code will create 4 boxes placed side by side, which will be 
dynamically positioned, according to the size of the screen. We define 
the following behavior: 




class = "col-lg-3"   




class = "col-md-4"   




class = "col-sm-6"  




  

    

      One of four columns
    
    

      One of four columns
    
    

      One of four columns
  	
    

      One of four columns