Kind of a special case of this: Change CSS of the clicked element.

If I have some divs like this:

    <div class="parent">
        <div class="child"></div>
    </div>

     <div class="parent">
        <div class="child"></div>
    </div>


    

I know I can assign a function to each parent div like:

const parent = document.querySelectorAll('.parent');
if(parent.length){
   for (let l of parent){
      l.addEventListener('click', (e)=>{
        l.classList.toggle('visible')
      })
   }
}

But how can I toggle the class .visible for the child div when the parent is clicked? Or alternatively add visibility:visible to the child div style.

Many thanks!