JavaScript“文档”不能用作关键字

Question

I have this code here in VSCode:

const form = document.querySelector('form');

The error I am getting is:

C:\Program Files\nodejs\node.exe boot.js 
helloworld
c:\Users\frase\OneDrive\Desktop\html\boot.js:2
const form = document.querySelector('form');
             ^

ReferenceError: document is not defined
    at Object.<anonymous> (c:\Users\frase\OneDrive\Desktop\html\boot.js:2:14)
    at Module._compile (internal/modules/cjs/loader.js:1157:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1177:10)
    at Module.load (internal/modules/cjs/loader.js:1001:32)
    at Function.Module._load (internal/modules/cjs/loader.js:900:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:74:12)
    at internal/main/run_main_module.js:18:47

Why is the document not working? The file name is referenced with the html file as <script src="boot.js"></script>

I have tried putting the script in the header and body tags.

Answer 1

document is available only when you are running javascript in a browser. It is not available by default.