Как сделать новую линию в HTML -абзаце
<p>
Will Mateson<br />
Box 61<br />
Cleveland, Ohio<br />
</p>
Shy Stork
<p>
Will Mateson<br />
Box 61<br />
Cleveland, Ohio<br />
</p>//setting this css style solving problem with new line in textContent
h1.setAttribute('style', 'white-space: pre;');
//add \r\n in text everywhere You want for line-break (new line)
h1.textContent = "this is line one \r\n and this is line 2";