JavaScript Newline Character

Question

lines = foo.value.split(/\r\n|\r|\n/);

is one way to split a string, but how do I join it back with newlines?

Also, I wonder if I is say linux which uses whichever newline character, then switch to windows, won't my web app break? The newlines become not recognized? Or maybe the browser does some conversion?

score 61 · Answer 1 · answered Dec 01 '10 at 03:59

61

If you want to join using newline characters, just do:

lines.join("\r\n");

But if you want to display on the HTML page, you'd want to wrap each line in <p></p> tags:

html = "<p>" + lines.join("</p><p>") + "</p>";

answered Dec 01 '10 at 03:59

David Tang

92,262
30
167
149

1
In HTML, you can also use lines.join("\r\n") and it works so long as you use the
```
 tag.
```
– Matthew Rideout Jun 19 '18 at 16:18
2

@MatthewRideout Or any element with `white-space: pre;`. – maxathousand Nov 22 '19 at 19:10

score 45 · Answer 2 · edited Jun 16 '20 at 00:11

45

You can use the Array object's join method to glue together array elements into a string:

lines.join("\r\n");

In CSS: remember to use

white-space: pre;

edited Jun 16 '20 at 00:11

Syntle

5,168
3
13
34

answered Dec 01 '10 at 03:56

Jacob Relkin

161,348
33
346
320

Is that only for Windows? In Linux the new line is `\n` isn't it? I guess the code will work anyways? – Jiew Meng Dec 01 '10 at 05:12
2

@JacobRelkin: didn't work for me using the .split('\r\n') but does work with .split(/\r?\n/) – SimplGy Nov 25 '12 at 16:58

score 28 · Accepted Answer · answered Dec 01 '10 at 04:23

28

Split it on /\r?\n/, in case the string includes the carriage returns with newlines.

join it with '\n', in any browser and any os.

answered Dec 01 '10 at 04:23

kennebec

102,654
32
106
127

17

In the node REPL you'll see a literal `\n` in the output for `['foo','bar'].join('\n')`, however if you run `console.log(['foo','bar'].join('\n'))` you'll see the expected result. Hope this helps someone else out there. – Jul 09 '15 at 19:26

score 0 · Answer 4 · answered Dec 01 '10 at 03:58

0

As said, join is the best, but here is the hard way (untested, I hope it's not too trivial):

var result;

for (i=0;i<lines.length;i++){
   result+=lines[i]+"\r\n"; //depends on OS
}

answered Dec 01 '10 at 03:58

Eran Medan

44,555
61
184
276

score 0 · Answer 5 · answered Jan 23 '23 at 10:36

0

The following seems a future-proof, os-independent code:

lines.join(`
`)

answered Jan 23 '23 at 10:36

Marinos An

9,481
6
63
96

score 0 · Answer 6 · answered Jan 31 '23 at 06:21

0

I used '\r' is OK, macOS 12.6, chrome 109.0.5414.119

lines.join('\r')

answered Jan 31 '23 at 06:21

DuskL

11
1
1
6

JavaScript Newline Character

6 Answers6

Linked