[Dilettante_Pro]

<header><div>Header Text Content</div></header>
<script>
const content = {
     parseContent: function(id) {
       let txt = [];
        document.querySelectorAll(id + ' div').forEach((div, i) => txt[i] = div.textContent);
        return txt;
    },
    header: function () { return this.parseContent('header') },
    main: function () { return this.parseContent('main') },
    footer: function () { return this.parseContent('footer') }
}
alert(content.header());

</script>