Can I select multiple tags using getElementsByTagName?

Question

I\'m using a javascript snippet in order for visitors to my site to increase the font size on all paragraphs using the following javascript:

function increas         


        

Answer 1

to select two tags at once? Yes we can create one loop for both at once.
This is your whole example. But one loop (one array) with both P and LI:

function increaseFontSize() {  

    Array.from(document.getElementsByTagName('p'))
        .concat(Array.from(document.getElementsByTagName('li'))).forEach(el => {


            if(el.style.fontSize) { 
                var s = parseInt(el.style.fontSize.replace("px",""));
            } else {   
                var s = 14;
            }

            if(s != max) {  
                s += 1; 
            } 
            el.style.fontSize = s+"px"
    });
} 

Explanation:
Array.from()
this is official way how to make real Array from a collection.
Some browsers might support forEach on HTMLCollection but it's not in specs.
Even so, they probably don't support concat() method.
Using from() will create a shallow copy of the collection.
That's an advantage on HTMLCollection because items could be modified during iteration and modification to elements inside the Array will still be a modification on original objects.

Now we have two standard Arrays and can use concat() to join them and forEach to iterate the joined result.