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.

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.

• javascript
• node.js
• for-loop

Share Improve this question Follow edited Oct 15, 2018 at 20:57 ibrahim mahrir 31.7k55 gold badges4949 silver badges7777 bronze badges asked Oct 15, 2018 at 20:53 Nidhi SharmaNidhi Sharma 47111 gold badge55 silver badges1818 bronze badges 1

• writeFile overwrites the file every time you call it. See the docs, specifically "writes data to a file, replacing the file if it already exists." – Heretic Monkey Commented Oct 15, 2018 at 20:56

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2 Answers 2

Sorted by: Reset to default 4

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(""));