我怎么能读一个文件与fs或没有它，但我想读一行一行?

Question

我想用fs读取一个文件，但到目前为止我无法做到这一点，从未显示控制台2222，为什么看不到控制台?

const inputFileName = "./input.txt";
fs.createWriteStream(outputFileName, { flags: "a" });
const fileStream = fs.createReadStream(inputFileName);
const file =  readline.createInterface({
input: fileStream,
crlfDelay: Infinity,
});
for await (const row of file) {
console.log(2222)
}

或者没有fs怎么读，没关系，但是我需要一行一行

Answer 1

您应该侦听line事件。下面是一段简单的代码:

let fs = require('fs');
let readline = require('readline');
let strInputFileName = 'input.txt';
let fRead = fs.createReadStream(strInputFileName); 

fRead.on('end', ()=>{ 
console.log('end'); 
}); 

let objReadline = readline.createInterface({ 
input: fRead, 
}); 
objReadline.on('line', (strLine)=>{ 
console.log(strLine)
}); 

Answer 2

可以了

function readTextFile(file) {
var rawFile = new XMLHttpRequest(); 
rawFile.open("GET", file, false); // open with method GET the file with the 
rawFile.onreadystatechange = function ()
{
if(rawFile.readyState === 4) // readyState = 4: request finished and response is ready
{
if(rawFile.status === 200) // status 200: "OK"
{
var allText = rawFile.responseText; //  Returns the response data 
var str_array = allText.split('n'); //convert to array
// use map function
str_array.map((value, key)=> {
console.log(value); //row per row data
})
}
}
}
rawFile.send(null); //Sends the request to the server Used for GET requests with param null
}
readTextFile("demo.txt"); //pass the file path