如何“等待”从回调函数获取值的属性？

function fetchData(callback) {
    setTimeout(() => {
        callback('Data fetched');
    }, 1000);
}

function processData() {
    fetchData((data) => {
        console.log(data); // 'Data fetched'
    });
}

processData();

function fetchData() {
    return new Promise((resolve) => {
        setTimeout(() => {
            resolve('Data fetched');
        }, 1000);
    });
}

async function processData() {
    const data = await fetchData();
    console.log(data); // 'Data fetched'
}

processData();

function fetchData() {
    return new Promise((resolve) => {
        setTimeout(() => {
            resolve('Data fetched');
        }, 1000);
    });
}

async function processData() {
    const data = await fetchData();
    console.log(data); // 'Data fetched'
}

processData();