js合并数组里面的数组

数据结构大概这样：

let order = [
      {
        goodsList:[
          {id:1,title:'产品1'},
          {id:2,title:'产品2'},
        ]
      },
      {
        goodsList:[
          {id:3,title:'产品3'},
          {id:4,title:'产品4'},
        ]
      }
    ]
    let goodsList = order.map(el => el.goodsList).flat()
    console.log(goodsList);