Question

我已阅读本地文件flight.txt

1 DFW BOM 2016-05-20 12:20 2016-05-21 02:40 1084.00 JetAirways 100
2 DFW DEL 2016-04-24 17:15 2016-04-25 07:20 1234.00 Lufthansa 100
3 DFW FRA 2016-06-05 13:30 2016-06-05 03:32 674.00 AmericanAirlines 100

用于读取打字稿文件的代码。

 populateFlightList() {
   let data = fs.readFileSync('flight.txt').toString('utf-8'); {
        let textByLine = data.split("\n")
        console.log(textByLine);

    };

现在我想循环并从文件中读取并将数据解析为飞行对象通过在每次迭代中创建一个新对象并将其添加到arraylist。

   try {
        Scanner fin = new Scanner(file);                
        while(fin.hasNext()) {
          int number = fin.nextInt();                 //flight numer
          String from = fin.next();                   //Departure airport
          String to = fin.next(); //Arrival airport
    }**Code in Java**

我如何在打字稿中这样做？

Answer 1

您可以使用readline模块一次读取一行。解析数据仍然是一个手工事件：

import * as fs from 'fs';
import * as rd from 'readline'

var reader = rd.createInterface(fs.createReadStream("W:\\tmp\\stack\\2\\data.txt"))

var data: Array<{ number: number; from: string; to: string}> = [];
reader.on("line", (l: string) => {
    var tokens = l.split(' ');
    var nr= parseInt(tokens[0]);
    var from = tokens[1];
    var to = tokens[2]
    console.log(`nr: ${nr} from ${from} to ${to}`);
    data.push({
        number: nr, from, to
    });
})
console.log(`Will be empty data has not yet been read ${data.length}` );

reader.on("close", ()=> {
    console.log(`Data has been read ${data.length}` );
    data.forEach(element => {
        console.log(`nr: ${element.number} from ${element.from} to ${element.to}`)
    });
})

每一行都会触发一次line事件。在读取整个文件并关闭文件后，close事件将触发，这是整个数据集可用的位置，我们每次构建一个条目，每次line事件发生。

有关readline模块的更多信息，请参阅documentation

循环遍历typescript中的文本文件

1 个答案: