js里什么是回调

function asyncOperation(callback) {
    setTimeout(() => {
        console.log("异步操作完成");
        callback();
    }, 2000);
}

function handleResult() {
    console.log("处理结果");
}

asyncOperation(handleResult);
console.log("继续执行其他任务");

function asyncOperation() {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            console.log("异步操作完成");
            resolve();
        }, 2000);
    });
}

asyncOperation().then(() => {
    console.log("处理结果");
});
console.log("继续执行其他任务");

async function run() {
    await asyncOperation();
    console.log("处理结果");
}

function asyncOperation() {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            console.log("异步操作完成");
            resolve();
        }, 2000);
    });
}

run();
console.log("继续执行其他任务");