For example, I used in a Firefox console:

[].forEach.call(document.getElementsByTagName('pre'), function(e){ 
   console.log(e);
})

For example, I used in a Firefox console:

[].forEach.call(document.getElementsByTagName('pre'), function(e){ 
   console.log(e);
})

You can use querySelectorAll to get same result

document.querySelectorAll('pre').forEach( (e) => { 
   console.log(e.textContent);
})

<pre>text 1</pre>
<pre>text 2</pre>
<pre>text 3</pre>