如何在异步函数中更改变量值？

function asyncFunction() {
  return new Promise((resolve, reject) => {
    // 异步操作
    setTimeout(() => {
      resolve('新的变量值');
    }, 1000);
  });
}

async function main() {
  let variable = '原始变量值';
  variable = await asyncFunction();
  console.log(variable);
}

main();

function asyncFunction(callback) {
  // 异步操作
  setTimeout(() => {
    callback('新的变量值');
  }, 1000);
}

function main() {
  let variable = '原始变量值';
  asyncFunction((newValue) => {
    variable = newValue;
    console.log(variable);
  });
}

main();

const EventEmitter = require('events');

class MyEmitter extends EventEmitter {}

const myEmitter = new MyEmitter();

function asyncFunction() {
  // 异步操作
  setTimeout(() => {
    myEmitter.emit('change', '新的变量值');
  }, 1000);
}

function main() {
  let variable = '原始变量值';
  myEmitter.on('change', (newValue) => {
    variable = newValue;
    console.log(variable);
  });
  asyncFunction();
}

main();