as shown in the figure, every time you click to create a new item, there will be a line of form, because traversing an array, so how to accurately assign the value to the corresponding object? 
 and how to delete a piece of data accurately? I use  data-index= "{{index}}"  to get the corresponding subscript, and then delete  splice (index, 1)  in the array, but delete it from the bottom to the top every time. 
  
