[javascript] How do I replace all line breaks in a string with <br /> elements?

How can I read the line break from a value with JavaScript and replace all the line breaks with <br /> elements?

Example:

A variable passed from PHP as below:

  "This is man.

     Man like dog.
     Man like to drink.

     Man is the king."

I would like my result to look something like this after the JavaScript converts it:

  "This is man<br /><br />Man like dog.<br />Man like to drink.<br /><br />Man is the king."

if you send the variable from PHP, you can obtain it with this before sending:

$string=nl2br($string);

Not answering the specific question, but I am sure this will help someone...

If you have output from PHP that you want to render on a web page using JavaScript (perhaps the result of an Ajax request), and you just want to retain white space and line breaks, consider just enclosing the text inside a <pre></pre> block:

var text_with_line_breaks = retrieve_some_text_from_php();
var element = document.querySelectorAll('#output');
element.innerHTML = '<pre>' + text_with_line_breaks + '</pre>';

It will replace all new line with break

str = str.replace(/\n/g, '<br>')

If you want to replace all new line with single break line

str = str.replace(/\n*\n/g, '<br>')

Read more about Regex : https://dl.icewarp.com/online_help/203030104.htm this will help you everytime.

Without regex:

str = str.split("\n").join("<br />");

This worked for me when value came from a TextBox:

string.replace(/\n|\r\n|\r/g, '<br/>');

Try

let s=`This is man._x000D_
_x000D_
     Man like dog._x000D_
     Man like to drink._x000D_
_x000D_
     Man is the king.`;_x000D_
     _x000D_
msg.innerHTML = s.replace(/\n/g,"<br />");

<div id="msg"></div>

Regardless of the system:

my_multiline_text.replace(/$/mg,'<br>');

This works for input coming from a textarea

str.replace(new RegExp('\r?\n','g'), '<br />');

It is also important to encode the rest of the text in order to protect from possible script injection attacks

function insertTextWithLineBreaks(text, targetElement) {
    var textWithNormalizedLineBreaks = text.replace('\r\n', '\n');
    var textParts = textWithNormalizedLineBreaks.split('\n');

    for (var i = 0; i < textParts.length; i++) {
        targetElement.appendChild(document.createTextNode(textParts[i]));
        if (i < textParts.length - 1) {
            targetElement.appendChild(document.createElement('br'));
        }
    }
}

If the accepted answer isn't working right for you then you might try.

str.replace(new RegExp('\n','g'), '<br />')

It worked for me.

For those of you who just want to allow max. 2 <br> in a row, you can use this:

let text = text.replace(/(\r?\n){2,}/g, '<br><br>');
text = text.replace(/(\r?\n)/g, '<br>');

First line: Search for \n OR \r\n where at least 2 of them are in a row, e.g. \n\n\n\n. Then replace it with 2 br

Second line: Search for all single \r\n or \n and replace them with <br>

If your concern is just displaying linebreaks, you could do this with CSS.

<div style="white-space: pre-line">Some test
with linebreaks</div>

Jsfiddle: https://jsfiddle.net/5bvtL6do/2/

Note: Pay attention to code formatting and indenting, since white-space: pre-line will display all newlines (except for the last newline after the text, see fiddle).