Remove line breaks with JavaScript

var stringWithLineBreaks = `
O boy 
I've got 
Breaks
`;
var stringWithoutLineBreaks = stringWithLineBreaks.replace(/(\r\n|\n|\r)/gm, "");//remove those line breaksString.replace(/(\r\n|\n|\r)/gm," ")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);