【js】 reduce、filter、map 数组链式调用求加和

       let data = [
          {hierarchy: '香蕉', count: 1},
          {hierarchy: '苹果', count: 2},
          {hierarchy: '葡萄', count: 3},
          {hierarchy: '梨', count: 4},
        ]
        let sum = data
          .filter((i) => i.hierarchy != '其他')
          .map((i) => i.count)
          .reduce((total, num) => {
            return total + num
          })
          console.log(sum)  => 10