问修复查询文档输出“未定义”，几分钟后显示存储在Node.js中的正确数据

EN

      firebase.initializeApp(firebaseConfig); //firebaseConfig is a variable that hold the configuration details

        //Query Funtion
        function queryFirestore() {

            var database = firebase.firestore();

            for (var i = 1; i <= 3; i++) {
                let id = database.collection("sampleCollection").doc(`id_${i}`);

                let getData = id.get().then(doc => {
                    if (!doc.exists) {
                        console.log("[!] Doc does not exists");
                    }
                    else {
                        var data = doc.data();
                        console.log(data['delayed']); //delayed is a boolean field in the Firestore Document
                    }

                }).catch(err => {
                    console.log("[:(] Error: ", err);
                })
            }

        }

queryFirestore();

undefined
false
false
true