const express = require('express'); const app = express(); const port = 4000; // CORSを許可する app.use(function(req, res, next) { res.header("Access-Control-Allow-Origin", "*"); res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept"); next(); }); app.get('/', (req, res) => { res.send('hello'); }); app.listen(port); 何をしているか ご存知の通り、セキュリティの観点から、オリジン(htmlが置かれたサーバー)以外のサ
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