如何使用 node.js 为文本文件的每一行创建一个数组条目 [英] How to create an array entry for each line of a text file using node.js

问题描述

我无法从 node.js 中文本文件的每一行创建一个数组条目

I am having difficulty creating an array entry out of each line of a text file in node.js

我的数组叫做temp".我可以在以下代码中对每一行进行 console.log:

My array is called "temp." I am able to console.log each line in the following code:

var temp = [];
const readline = require('readline');
const fs = require('fs');
let rl = readline.createInterface({
    input: fs.createReadStream('./lib/Sphinx.txt')
});
let line_no = 0;
rl.on('line', function(line) {
    line_no++;
    console.log(line); //this successfully prints out every line
    temp.push(line); //this would ideally create a new array entry for each line

});

但是，当我运行此代码时:

However, when I run this code:

console.log(temp.length)
//returns 0
console.log(temp.size)
//returns undefined

异步函数调用导致这种情况发生.结果，我无法访问函数本身之外的数组值，这是唯一的目标.

Asynchronous function calls are causing this to happen. As a result, I am unable to access the array values outside of the function itself, which is the only objective.

感谢帮助.谢谢，纳库尔

Help is appreciated. Thanks, Nakul

推荐答案

rl.on('line', function (line) {
    line_no++;
    console.log(line); //this successfully prints out every line
    temp.push(line); //this would ideally create a new array entry for each line
}).on('close', function (line) {
    // EOF
    console.log(temp);
    console.log(temp.length);
});;

• 编写 console.log(temp.length) 而不是 console.log(temp.size) 应该可以工作

  • Write console.log(temp.length) instead of console.log(temp.size) that should work

    您应该在逐行读取时获得完整的数组，即在 close 事件上.

    You should get complete array at the end of your line by line read, i.e. on close event.

    这篇关于如何使用 node.js 为文本文件的每一行创建一个数组条目的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！