js事件函数和异步

// 使用回调函数的异步事件处理
document.getElementById('myButton').addEventListener('click', function() {
    console.log('Button clicked!');
    setTimeout(function() {
        console.log('Async operation completed!');
    }, 2000);
});

// 使用Promise的异步事件处理
document.getElementById('myButton').addEventListener('click', function() {
    console.log('Button clicked!');
    fetchData().then(function(data) {
        console.log('Data fetched:', data);
    });
});

function fetchData() {
    return new Promise(function(resolve, reject) {
        setTimeout(function() {
            resolve('Some data');
        }, 2000);
    });
}

// 使用async/await的异步事件处理
document.getElementById('myButton').addEventListener('click', async function() {
    console.log('Button clicked!');
    try {
        const data = await fetchData();
        console.log('Data fetched:', data);
    } catch (error) {
        console.error('Error fetching data:', error);
    }
});