javascript replace newline

var r = "I\nam\nhere";
var s = r.replace(/\n/g,' ');

let multilineString = `My
text\r1\r\n2\n3\n\r4
is
here`;

let htmlText = multilineString.replace(/(\r\n|\n\r|\r|\n)/g, '<br>');

console.log('Multiline string: ' + multilineString);
console.log('HTML text: ' + htmlText);