如何在循环中使用回调

function asyncOperation(value, callback) {
    setTimeout(() => {
        console.log(`异步操作完成: ${value}`);
        callback(null, value * 2); // 成功时调用回调
    }, 1000);
}

function processValues(values) {
    let results = [];
    let completed = 0;

    values.forEach((value, index) => {
        asyncOperation(value, (err, result) => {
            if (err) {
                console.error(`操作失败: ${value}`);
                return;
            }
            results[index] = result;
            completed++;

            if (completed === values.length) {
                console.log('所有操作完成', results);
            }
        });
    });
}

processValues([1, 2, 3, 4]);

function asyncOperation(value) {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            console.log(`异步操作完成: ${value}`);
            resolve(value * 2);
        }, 1000);
    });
}

async function processValues(values) {
    let results = [];

    for (let value of values) {
        let result = await asyncOperation(value);
        results.push(result);
    }

    console.log('所有操作完成', results);
}

processValues([1, 2, 3, 4]);