原生js特效大全

window.addEventListener('scroll', function() {
    const nav = document.querySelector('.navbar');
    if (window.scrollY > 50) {
        nav.classList.add('active');
    } else {
        nav.classList.remove('active');
    }
});

function openModal() {
    const modal = document.getElementById('myModal');
    modal.style.display = 'block';
}

function closeModal() {
    const modal = document.getElementById('myModal');
    modal.style.display = 'none';
}

let slideIndex = 0;
showSlides();

function showSlides() {
    const slides = document.getElementsByClassName('mySlides');
    for (let i = 0; i < slides.length; i++) {
        slides[i].style.display = 'none';
    }
    slideIndex++;
    if (slideIndex > slides.length) {slideIndex = 1}
    slides[slideIndex-1].style.display = 'block';
    setTimeout(showSlides, 2000); // 更改图片的时间间隔
}

function validateForm() {
    const input = document.forms["myForm"]["fname"].value;
    if (input == "") {
        alert("Name must be filled out");
        return false;
    }
}