這是我的代碼，它是用Node express構建的。在接下來的（“路徑”）不2種類似的情況一致的工作。let express = require("express");let app = express();let router = express.Router();router.use("/message/:id", function (req, res, next) {    console.log(typeof req.params.id);    if (req.params.id === 1 + "") {        console.log("the current id is 1");        next();    } else if (req.params.id === 2 + "") {        console.log("the current id is 2");        next("route");    } else if (req.params.id === 3 + "") {        console.log("the current id is 3");        next("router");    } else {        res.send("no id matched");    }}, function (req, res) {    res.send("this is a scenario when id is 1");});router.use("/message/:id", function (req, res) {    res.send("this is a details page");});app.use("/", router, function (req, res) {    res.send("this is triggered by the app");});app.listen(8080, function () {    console.log("Please visit localhost:8080");});當我輸入這樣的 URL 地址：“ http://localhost:8080/message/2 ”時，Node REPL 控制臺輸出：“當前 id 為 2”，網頁顯示：“這是 id 為1”。我對此很困惑。根據 express 的官方文檔， next("route") 會將控制權傳遞給下一個路由。所以我認為它應該顯示"this is a details page"而不是"this is a scenario when id is 1"。為什么？為了弄清楚更多，我還對代碼進行了一些更改：let express = require("express");let app = express();let router = express.Router();router.get("/message/:id", function (req, res, next) {    console.log(typeof req.params.id);    if (req.params.id === 1 + "") {        console.log("the current id is 1");        next();    } else if (req.params.id === 2 + "") {        console.log("the current id is 2");        next("route");    } else if (req.params.id === 3 + "") {        console.log("the current id is 3");        next("router");    } else {        res.send("no id matched");    }}, function (req, res) {    res.send("this is a scenario when id is 1");});router.get("/message/:id", function (req, res) {    res.send("this is a details page");});我簡單地取代了router.use與router.get，而這一次，當我重溫“ HTTP：//本地主機：8080 /消息/ 2 ”，網頁顯示“這是一個詳細信息頁面”。為什么在這兩種情況下結果不同？