javascript - 以不可变的方式过滤2层数组对象

Question

我有一个以下格式的对象数组，旨在以不可变方式进行过滤。可以使用pure javascript、es6 或lodash 库来完成。

注意:这里的关键点是以不可变方式进行过滤。

逻辑:

if (all product qty in the first level object is empty string or 0) {
    do not show that first that level object
}

if (product qty is empty string or 0) {
    do not show that product
}

输入:

 let targetArray = [{
     recipient: '1',
     product: [{
             productId: '1',
             qty: '2'
         }, {
             productId: '2',
             qty: '0'
         }
     ]
 }, {
     recipient: '2',
     product: [{
             productId: '1',
             qty: '0'
         }, {
             productId: '3',
             qty: ''
         }
     ]
 },
 ]

预期输出:

[
    {
        recipient: '1',
        product: [{
          productId: '1',
          qty: '2'
        }]
    }
]

Answer 1

我会使用reduce来实现

let targetArray = [
    {
        recipient: '1',
        product: [{
          productId: '1',
          qty: '2'
        }, {
            productId: '2',
            qty: '0'
        }]
    },
   {
        recipient: '2',
        product: [{
          productId: '1',
          qty: '0'
        }, {
            productId: '3',
            qty: ''
        }]
    },
]

let filtered = targetArray.reduce((acc,curr) => {
  let products = curr.product.filter(product => parseInt(product.qty) > 0);
  
  if (products.length === 0) {
    return acc;
  }
  
  acc.push({...curr, product: products});
  return acc;
}, [])

console.log({filtered});
console.log({targetArray});