Edit string in text file

[8022]

this is my code 

var accelData = [];

if (Accelerometer) {
const accel = new Accelerometer({ frequency: 1 });
accel.addEventListener("reading", () => {
accelData.text = JSON.stringify({
x: accel.x ? accel.x.toFixed(1) : 0,
y: accel.y ? accel.y.toFixed(1) : 0,
z: accel.z ? accel.z.toFixed(1) : 0
});

});
sensors.push(accel);
accel.start();
} else {
accelLabel.style.display = "none";
accelData.style.display = "none";
}

var timer = setInterval(function(){
file = fs.openSync("utf8.txt" , "w+");
fs.writeSync(file , accelData.text) ;

let utf8_read = fs.readFileSync("utf8.txt", "utf-8");
console.log("UTF-8 Data: " + utf8_read);

fs.closeSync(file)

},5000)

I want is to save the sensor data in text every 5 seconds and see the size of the text file.

but ...

[오후 4:03:52]Unhandled exception: ReferenceError: file is not defined

[오후 4:03:57]Unhandled exception: Error: Couldn't open file: utf8.txt

If you use writeFileSync, it is said that if there is no file, it is created. Why is there no file?

And if you don't open and write the file like that, the text file will be created normally.

Could anyone please tell me this?

[JonFitbit · Accepted solution]

I'd recommend reading the filesystem guide here https://dev.fitbit.com/build/guides/file-system/

You were missing var, let or const here:

[오후 4:03:52]Unhandled exception: ReferenceError: file is not defined

let file = fs.openSync("utf8.txt" , "w+");