Page({
  onLoad() {
    let a = {x: 1}
    let b = {x: 2}
    [a, b].forEach(({x}) => {console.log(x);})
  }
})

报错：

TypeError: Cannot read property 'forEach' of undefined

换成下面这样正常：

Page({
  onLoad() {
    let a = {x: 1}
    let b = {x: 2}
    // [a, b].forEach(({x}) => {console.log(x);})
    let os = [a, b]
    os.forEach(({x}) => {console.log(x);})
  }
})