javascript - 此处意外的模块导入或导出语句

Question

我在从代码导入 JS 脚本时遇到问题。我有一个 canvas 游戏，我想导入我的类而不是用 HTML 定义它们。但是当我在 Edge 中运行我的代码时，它会抛出一个错误。

初始化.js

import {Tram} from "./tram/tram"

var body;
var curScreen = "menu";
var canvas = document.createElement("canvas");
canvas.width = 1920;
canvas.height = 1080;
var ctx = canvas.getContext("2d");
var tex = {};
var corrHeight = 
loadTextures();

window.onload = function () {
    body = document.body;
    body.appendChild(canvas);

    window.onclick = function () {
        if (body.requestFullscreen) {
            body.requestFullscreen();
        }
        else if (body.msRequestFullscreen) {
            body.msRequestFullscreen();
        }
        else if (body.mozRequestFullScreen) {
            body.mozRequestFullScreen();
        }
        else if (body.webkitRequestFullscreen) {
            body.webkitRequestFullscreen();
        }
    };

    mainLoop();
};

function updateCanvasRect() {
    canvas.width = brect.width;
    canvas.height = brect.height;
    var prop = 16 / 9;
    tex.sky.img.height = brect.height;
    tex.sky.img.width = brect.height * prop;
    tex.sky.patt = ctx.createPattern(tex.sky.img, "repeat-x");
}

function loadTextures() {
    tex.sky = importTexture("base/sky");
}

我有以下文件夹结构:

  ts2d/
    img/
      ...
    base/
      ...
      tram/
        tram.js
        ...
      init.js
      load.js
    main.js
    index.html

Answer 1

解决了!问题出在 HTML 脚本声明中:

我使用了这段代码:

<script src="base/init.js"></script>

但我不知道，我需要指定 type 属性，import 下面的代码效果很好!

<script src="base/init.js" type="module"></script>

UPD:变量只是文件范围的，用于另一个文件导出变量:

var myVar = "string";
export {myVar};

然后在你的文件中

import {myVar} from "<file>";