CODEWITHSUNDEEP
javascriptnode.js
pourmesomecode
pourmesomecode

Reputation: 4358

Iterate over line of string nodejs

So I have a massive text file that looks like : 

e10_04txyscelsxeu4j63dx49b7nh3dzsn_q33_fdgskfdn_q53
e2_05txyscelsxeu4j63dx49b7nh3dzsn_q11_fdgskfdn_q13
e9_01_1txyscelsxeu4j63dx49b7nh3dzsn_q06_fdgskfdn_q42
e10_23txyscelsxeu4j63dx49b7nh3dzsn_q04_fdgskfdn_q41

There's a list of these random strings. I'm trying to iterate over each of the lines, grab the first 10 letters/numbers and spit them out somewhere so I can do something with them.

At the moment i'm iterating over every letter like so : 

const fs = require('fs');

fs.readFile('myData', 'utf8', (err, data) => {

    for (var i = 0, j = data.length; i < j; i++) {
        if (i == 10) {
            console.log('test');
        } else {

        }
    }
});

Is there anyway I can do what i'm trying to do?

Thanks!

Upvotes: 0

Views: 1757

Answers (2)

Alongkorn
Alongkorn

Reputation: 4217

You should use readline module as @jordanhendrix said.

To grapes first 10 characters for each line, you can use

line.substring(0, 10);

Upvotes: 1

omarjmh
omarjmh

Reputation: 13896

You could read the file one line at a time usingreadline:

// this creates a read stream 

var reader = require('readline').createInterface({
  input: require('fs').createReadStream('file.in')
});

// then here you would be able to manipulate each line:

reader.on('line', function (line) {
  console.log('The current line is: ', line);
});

Upvotes: 4

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