How to implement jump page in javascript

JavaScript is a commonly used programming language that is often used in web development. In web design, the function of jumping to the page is often used. In this process, JavaScript jumping to the page is one of the most commonly used methods. JavaScript can also help users optimize pages and enhance user experience. This article will introduce you to the relevant knowledge of using JavaScript to implement jump pages and optimize pages.

1. How to implement JavaScript jump page

There are many methods for JavaScript jump page, such as using URL link, using location.href, using window.location.replace, etc. Below we will explain these methods to you in detail.

Method 1: Use URL link

This method is very simple. You only need to add a hyperlink to the HTML code. The code is as follows:

<a href="http://www.baidu.com">百度一下</a>

When the user clicks When you click this link, your browser will jump directly to Baidu's website.

Method 2: Use location.href

It is very common to use the location.href method to jump to JavaScript pages. The code is as follows:

location.href='http://www.baidu.com';

This method can be used in JavaScript Called directly, it will transfer the current page of the browser to my Baidu website.

Method 3: Use window.location.replace

Use the window.location.replace method to update the URL address of the page when the page jumps. The code is as follows:

window.location.replace('http://www.baidu.com');

This method will update the URL of the page when the page jumps, and can also avoid problems such as the back button.

Method 4: Use window.location.assign

Use the window.location.assign method to take a URL as a parameter and load the document being displayed to the location specified by the URL. The code is as follows:

window.location.assign('http://www.baidu.com');

This method is basically the same as the location.href method, but the window.location.assign method may be more reliable in some cases.

2. How to optimize the page

After you implement JavaScript page jump, you can also use JavaScript to optimize the website page. Here are some common JavaScript optimization methods for you.

Method 1: Use dynamic loading

Dynamic loading means that when the page is loaded, only the required part of the content is loaded instead of loading all the content. This approach can reduce page load time and improve user experience. For example:

window.onload = function() {
    var myImage = new Image();
    myImage.src = 'http://example.com/wp-content/uploads/2017/08/example.png';
    document.body.appendChild(myImage);
}

This code will dynamically load an image after the page is loaded, instead of loading all the images at the beginning.

Method 2: Use caching

Using caching can reduce repeated download times and improve website access speed. To use caching in JavaScript, you can use the localStorage object. For example:

if (localStorage.getItem('visited')) {
    alert('欢迎再次访问！');
} else {
    alert('欢迎访问我们的网站！');
    localStorage.setItem('visited', 'yes');
}

This code will check whether the user has visited the website. If it has been visited, the data will be read directly from the cache without downloading again.

Method 3: Use lazy loading of images

Lazy loading of images means not automatically loading all images when the page is loaded, but waiting until the user scrolls the page or other conditions are met before loading the images. This method can speed up website loading and improve user experience. For example:

function isInViewport(element) {
    var rect = element.getBoundingClientRect();
    return (
        rect.top >= 0 &&
        rect.left >= 0 &&
        rect.bottom <= (window.innerHeight || document.documentElement.clientHeight) &&
        rect.right <= (window.innerWidth || document.documentElement.clientWidth)
    );
}

var images = document.querySelectorAll(&#39;img[data-src]&#39;);
function preloadImage(img) {
    var src = img.getAttribute(&#39;data-src&#39;);
    if (!src) {
        return;
    }
    img.src = src;
    img.removeAttribute(&#39;data-src&#39;);
}

var imgOptions = {
    threshold: 0,
    rootMargin: "0px 0px 0px 0px"
};

var imgObserver = new IntersectionObserver(
    (entries, imgObserver) => {
        entries.forEach(entry => {
            if (entry.isIntersecting) {
                preloadImage(entry.target);
                imgObserver.unobserve(entry.target);
            }
        });
    }, 
    imgOptions
);

images.forEach(image => {
    imgObserver.observe(image);
});

This code will only start loading images when the user scrolls the page, instead of loading all images at the beginning.

3. Summary

In web design, using JavaScript to jump to pages can help users access the desired website more quickly. At the same time, JavaScript can also improve the user's access experience by optimizing the page, such as using dynamic loading, caching, and lazy loading of images. Whether in web design or web development, JavaScript is an essential tool.

The above is the detailed content of How to implement jump page in javascript. For more information, please follow other related articles on the PHP Chinese website!