I have a sample array as follows
var arr = [ [ 1373628934214, 3 ],
[ 1373628934218, 3 ],
[ 1373628934220, 1 ],
[ 1373628934230, 1 ],
[ 1373628934234, 0 ],
[ 1373628934237, -1 ],
[ 1373628934242, 0 ],
[ 1373628934246, -1 ],
[ 1373628934251, 0 ],
[ 1373628934266, 11 ] ]
I would like to write this array to a file such as I get a file as follows
1373628934214, 3
1373628934218, 3
1373628934220, 1
......
......
This question is related to
javascript
node.js
We can simply write the array data to the filesystem but this will raise one error in which ',' will be appended to the end of the file. To handle this below code can be used:
var fs = require('fs');
var file = fs.createWriteStream('hello.txt');
file.on('error', function(err) { Console.log(err) });
data.forEach(value => file.write(`${value}\r\n`));
file.end();
\r\n
is used for the new Line.
\n
won't help. Please refer this
To do what you want, using the fs.createWriteStream(path[, options]) function in a ES6 way:
const fs = require('fs');
const writeStream = fs.createWriteStream('file.txt');
const pathName = writeStream.path;
let array = ['1','2','3','4','5','6','7'];
// write each value of the array on the file breaking line
array.forEach(value => writeStream.write(`${value}\n`));
// the finish event is emitted when all data has been flushed from the stream
writeStream.on('finish', () => {
console.log(`wrote all the array data to file ${pathName}`);
});
// handle the errors on the write process
writeStream.on('error', (err) => {
console.error(`There is an error writing the file ${pathName} => ${err}`)
});
// close the stream
writeStream.end();
A simple solution is to use writeFile :
require("fs").writeFile(
somepath,
arr.map(function(v){ return v.join(', ') }).join('\n'),
function (err) { console.log(err ? 'Error :'+err : 'ok') }
);
Remember you can access good old ECMAScript APIs, in this case, JSON.stringify()
.
For simple arrays like the one in your example:
require('fs').writeFile(
'./my.json',
JSON.stringify(myArray),
function (err) {
if (err) {
console.error('Crap happens');
}
}
);
Source: Stackoverflow.com