inherit.js

function DOM(selector) {
    if (!(this instanceof DOM)) {
        return new DOM(selector);
    }

    // Helper for pushing an array-like object onto the current instance
    Array.prototype.push.apply(this, document.querySelectorAll(selector));
}

_inheritFrom(DOM, Array);

// Idea taken from babel when using the likes of "class Child extend Parent { ... }"
function _inheritFrom(child, parent) {
    const parentProto = parent && parent.prototype ? parent.prototype : parent;
    child.prototype = Object.create(parentProto, {
        constuctor: {
            value: parent,
            configurable: true,
            enumerable: false,
            writable: true
        }
    });

    Object.setPrototypeOf(child, parent);
}

// Example

// The IIFE is a way of being able to re-use const variables in the Chrome Snippets without reloading
(function () {
    const $hyperLinks = DOM('a');
    $hyperLinks.forEach(el => console.log(el));

    const $navLinks = $hyperLinks.filter(el => el.classList.contains('header-nav-link'));
    console.log($navLinks);
}());