回调函数
代码语言：javascript
复制function say(callback) {
setTimeout(() => {
console.log('11111')
callback()
}, 1000)
}
say(() => {
console.log('2222')
})
Promise
代码语言：javascript
复制new Promise(function (resolve, reject) {
setTimeout(() => {
console.log('11111')
resolve()
}, 1000)
}).then(() => {
console.log('2222')
})
async/await
代码语言：javascript
复制async function f1() {
var res = await new Promise(function (resolve, reject) {
setTimeout(() => {
console.log('11111')
resolve('2222')
}, 1000)
})
console.log(res)
}
f1()
