innerHTML innerText
<div></div>
<script>
var div=document.getElementsByTagName('div');
console.log(div[0]);
div[0].innerText='today is Monday';
// for (let i=0;i<5**8;i++);
div[0].innerHTML='today is <strong>Monday</strong>' +
'<span>.</span>';
console.log(div[0].innerHTML);
console.log(div[0].innerText);
</script>
前者保留<strong>等表示,后者只显示文本,且如有换行则去掉换行