Klasse "dark" zu body hinzufügen bei Klick auf Button mit class="mode-changer"

gistfile1.txt

<script>

const darkBtn = document.querySelector('.mode-changer');
const bodyEl = document.querySelector('body');

const darkMode = () => {
    bodyEl.classList.toggle('dark')
}

darkBtn.addEventListener('click', () => {
    // Get the value of the "dark" item from the local storage on every click
    setDarkMode = localStorage.getItem('dark');

    if(setDarkMode !== "on") {
        darkMode();
        // Set the value of the itwm to "on" when dark mode is on
        setDarkMode = localStorage.setItem('dark', 'on');
    } else {
        darkMode();
        // Set the value of the item to  "null" when dark mode if off
        setDarkMode = localStorage.setItem('dark', null);
    }
});

// Get the value of the "dark" item from the local storage
let setDarkMode = localStorage.getItem('dark');

// Check dark mode is on or off on page reload
if(setDarkMode === 'on') {
    darkMode();
}
</script>