I have an array of data which i want to loop over and while looping over I want to write them to the same file. How i can achieve the same, my following code will only print the last iteration.
for (j = 0; j < arrayPart.length; j++){
fs.writeFileSync('message.txt', arrayPart[j])
}
message.txt will have the last value of arrayPart.
Instead of opening/writing/closing at every iteration I would open a write stream, write inside the loop and close at the end:
const message = fs.createWriteStream(__dirname + "./message.txt");
for (let j = 0; j <arrayPart.length; j++){
message.write(arrayPart[j]);
}
message.close();
Or you just join the array and write all at once:
fs.writeFileSync('message.txt', arrayPart.join(""));
Just join the array and write to the file once:
fs.writeFileSync('message.txt', arrayPart.join(""));
arrayPart.join("") will result in a string. If you want to write only the first 200 character of that string, you could slice it like fs.writeFileSync('message.txt', arrayPart.join("").slice(0, 200));fs.writeFileSync('message.txt', Buffer.from(arrayPart.join(""), "utf8").slice(0, 200));join won't work as expected, you might want to use Buffer.concat for that: fs.writeFileSync('sample.jpg', Buffer.concat(arrayPart)). Buffer.concat returns a buffer, so you can use slice on it like before.
writeFileoverwrites the file every time you call it. See the docs, specifically "writes data to a file, replacing the file if it already exists."