Uniapp gets the instance of the previous page

The following is the stack list of all pages

let pages = getCurrentPages(); //  Stack of all pages 
let prevPage = pages[pages.length - 2]; //  The example on the previous page 
prevPage.$vm----> This is the example on the previous page 

 For example, to operate on the previous page data Defined name
prevPage.$vm.name = ' assignment '