js判断网页是否存在

async function checkUrlExists(url) {
    try {
        const response = await fetch(url, { method: 'HEAD' });
        return response.ok; // 如果HTTP状态码在200-299之间，则返回true
    } catch (error) {
        console.error('Error checking URL:', error);
        return false;
    }
}

// 使用示例
checkUrlExists('https://example.com/page.html').then(exists => {
    console.log('URL exists:', exists);
});

function checkElementExists(selector) {
    return document.querySelector(selector) !== null;
}

// 使用示例
if (checkElementExists('#myElement')) {
    console.log('Element exists!');
} else {
    console.log('Element does not exist.');
}