使用Promise过程中resolve或reject后，后面代码还会执行，默认加return较妥

[youngjuning]

new Promise((resolve) => {
  console.log(1)
  resolve()
  console.log(2)
}).then(() => {
  console.log(3)
})
console.log(4)

输出顺序：1 2 4 3

new Promise((resolve) => {
  console.log(1)
  return resolve()
  console.log(2)
}).then(() => {
  console.log(3)
})
console.log(4)

输出顺序：1 4 3