test this point

index.js

@@ -87,7 +87,7 @@ const app=createApp({
       console.log("---------tomcat server----------");
       console.log("this.tomcat_res : "+this.tomcat_res);
       console.log("------this.books : "+this.books);
-      const books=this.books;
+      const _books=this.books;
       // console.log("------this : "+this);
       const request = new XMLHttpRequest();
       request.onload=function(){
@@ -107,7 +107,7 @@ const app=createApp({
         console.log("this.tomcat_res : "+this.tomcat_res);
         alert("this.tomcat_res : "+this.tomcat_res);
         
-        // console.log("------books : "+books);
+        console.log("------  _books : "+_books);
         // console.log("------this.books : "+this.books);
         // books.add(res[0]);