我在學習Node.js,並學習高級Javascript。在這段代碼中,他們使用節點製作一個HTTP服務器,一切正常,容易:dir是什麼? dir +「/」:「」是什麼意思?
var http = require("http");
var path = require("path");
var fs = require("fs");
var extensions = {
".html": "text/html",
".css": "text/css",
".js": "application/javascript",
".png": "image/png",
".gif": "image/gif",
".jpg": "image/jpeg"
};
http.createServer(function(req, res) {
var filename = path.basename(req.url) || "index.html";
var ext = path.extname(filename);
var dir = path.dirname(req.url).substring(1);
var localPath = __dirname + "/public/";
if (extensions[ext]) {
localPath += (dir ? dir + "/" : "") + filename;
path.exists(localPath, function(exists) {
if (exists) {
getFile(localPath, extensions[ext], res);
} else {
res.writeHead(404);
res.end();
}
});
}
}).listen(8000);
但是,我不明白的結構dir ? dir
做什麼(爲什麼「:」」「)?
[Conditional operator](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator) –
Thx,很有幫助 – gurrumo