How does vue view the data of a variable in the console?

for example, how should I view the data of test in the console? Why did I report an error like that in my picture 

<!DOCTYPE html>
<html>
<head>
   <title></title>
   <style type="text/css">
   </style>
   <script src="vue.js"></script>
   <script type="text/javascript">
      window.onload=function(){
         var vm=new Vue({
               el:"-sharpapp",
               data:{
                test:111
               }
         })
      }
   </script>
</head>
<body>
<div id="app">
</div>
</body>
</html>

Vue.js
Apr.17,2021 
var vm = new Vue({...})
console.log(vm.test);

read the first item output in the console in English. Click on the next link. When
is done, you will find that debugging is so convenient

vue devtools

.

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MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1eb793a-4841f.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1eb793a-4841f.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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