摘要：
执行过程：宏任务和微任务（一个宏任务配置多个微任务）：每次执行微任务队列时，都会完全执行并清除控制台。日志（“主”）进程。nextTick（（）=˃｛console.log（'process.nextTick1'）｝）setTimeout
执行流程：
宏任务和微任务（一个宏任务配多个微任务）：每次执行微任务队列会全部执行完并清空
console.log('main')
process.nextTick( () => {
console.log('process.nextTick1')
})
setTimeout(() => {
console.log('setTimeout')
process.nextTick(() => {
console.log('process.nextTick2')
})
}, 0)
new Promise((resolve, reject) => {
console.log('promise')
resolve()
}).then(() => {
console.log('promise then')
})
console.log('main2')执行结果
main
promise
main2
process.nextTick1
promise then
setTimeout
process.nextTick2
图示：
