js ajax嵌套ajax

$.ajax({
    url: 'api/first',
    type: 'GET',
    success: function(data1) {
        // 使用data1发起第二个请求
        $.ajax({
            url: 'api/second',
            type: 'POST',
            data: { firstData: data1 },
            success: function(data2) {
                // 使用data2发起第三个请求
                $.ajax({
                    url: 'api/third',
                    type: 'GET',
                    success: function(data3) {
                        console.log('Final data:', data3);
                    },
                    error: function(err) {
                        console.error('Error in third request:', err);
                    }
                });
            },
            error: function(err) {
                console.error('Error in second request:', err);
            }
        });
    },
    error: function(err) {
        console.error('Error in first request:', err);
    }
});

function fetchData(url, method, data = null) {
    return new Promise((resolve, reject) => {
        $.ajax({
            url: url,
            type: method,
            data: data,
            success: resolve,
            error: reject
        });
    });
}

fetchData('api/first', 'GET')
    .then(data1 => {
        return fetchData('api/second', 'POST', { firstData: data1 });
    })
    .then(data2 => {
        return fetchData('api/third', 'GET');
    })
    .then(data3 => {
        console.log('Final data:', data3);
    })
    .catch(err => {
        console.error('Error:', err);
    });

async function fetchAllData() {
    try {
        const data1 = await fetchData('api/first', 'GET');
        const data2 = await fetchData('api/second', 'POST', { firstData: data1 });
        const data3 = await fetchData('api/third', 'GET');
        console.log('Final data:', data3);
    } catch (err) {
        console.error('Error:', err);
    }
}

fetchAllData();