Handle a click outside of a parent element

click-outside-element.js

// the parent, avoid clicks inside this element
const parent = document.getElementById('parent');

window.addEventListener('click', e => {
    
    let elem = e.target;

    // loop through the target's parent nodes to see if it matches 
    for ( ; elem && elem !== document; elem = elem.parentNode ) {
        
        if(elem === parent) {
            // if it matches then get out
            return false;
        }
    }

    // we know that the click came from outside the parent
  
});