JavaScript: Get an array of lines from the specified file

JavaScript fundamental (ES6 Syntax): Exercise-159 with Solution

Read File Lines into Array

Write a JavaScript program to get an array of lines from the specified file.

• Use fs.readFileSync() to create a Buffer from a file.
• Convert buffer to string using buf.toString(encoding) function.
• Use String.prototype.split(\n) to create an array of lines from the contents of the file.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2 
// Import the 'fs' module for file system operations in Node.js
const fs = require('fs');

// Define a function 'readFileLines' that reads the contents of a file and returns an array of lines
// It takes one parameter:
// 1. 'filename': The name of the file to read

const readFileLines = filename =>
  // Read the contents of the file synchronously using 'fs.readFileSync'
  fs
    .readFileSync(filename)
    // Convert the buffer to a UTF-8 encoded string and split it into an array of lines using '\n' as the delimiter
    .toString('UTF8')
    .split('\n');

// Call the 'readFileLines' function with the filename 'test.txt' and store the result in 'arr'
let arr = readFileLines('test.txt');

// Log the array 'arr' containing the lines read from the file
console.log(arr); // Logs ['line1', 'line2', 'line3']

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-159-1 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript program that reads a text file and splits its contents into an array of lines using FileReader API.
• Write a JavaScript function that accepts a file input and returns an array of non-empty lines from the file.
• Write a JavaScript program that reads a file asynchronously and processes its content into an array of trimmed strings.
• Write a JavaScript program that converts a file’s content into an array of lines, filtering out comment lines starting with "#".

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