<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <style> body { font-family: "Microsoft YaHei", serif; } body, dl, dd, p, h1, h2, h3, h4, h5, h6 { margin: 0; } ol, ul, li { margin: 0; padding: 0; list-style: none; } img { border: none } </style> </head> <body> <script> // var a = 10-vue-router; // alert(a); // function a() { // alert(20) // } //10-vue-router 报错 // 1定义 // function a() { // Alert (20 is) // } // 2 performs // A-VUE-Router = 10; // Alert (A) // 10-VUE-Router // A () // error var A; Alert (A); function A () { Alert ( 20 is ) } // function block 20 is </ Script > </ body > </ HTML >