Javascript：如何過濾數組中的 object

Question

我有一個由 object 組成的數組，它具有 categoryName(string) 字段和一個數組(plants)。

我想使用植物名稱進行過濾，最好的方法是什么？

我試過但它只返回植物數組，忽略 categoryName

this.itemList.map(item => item.plants.filter(p=> p.name.toLowerCase().includes(this.searchTerm.toLowerCase())));

結構

[

 [
    categoryName: "Heating"
    plants: Array(2)
    0: {plantId: 35, name: "Alston Oven", description: "Oven", plantCategoryId: 2, whenCreated: "1519357215942", …}
    1: {plantId: 19, name: "Gregs Oven", description: null, plantCategoryId: 2, whenCreated: "1516830724579", …}
 ]



  [
    categoryName: "Refrigeration"
    plants: Array(4)
    0: {plantId: 13, name: "Fridge 1 ", description: "Walk in fridge" …}
    1: {plantId: 5, name: "Fridge 2 Updated", description: "Description of Fridge 2" …}
    2: {plantId: 4, name: "Fridge"....} 
  ]
]

Answer 1

在外部數組上使用filter() ，在內部plants數組上使用some() 。

這不會過濾掉植物陣列中的特定植物，而是保持整個陣列完好無損。 不清楚是否需要過濾子數組

const term = this.searchTerm.toLowerCase(),
      res = this.itemList.filter(({plants}) => plants.some(({name}) => name.toLowerCase().includes(term)))

Answer 2

嘗試：

this.itemList.map(function(a) {
    return {
        categoryName: a.categoryName,
        plants: a.plants.filter(p => p.name.toLowerCase().includes(this.searchTerm.toLowerCase()))
}}).filter(a => a.plants.length > 0)

Answer 3

請試試這個例子

 const searchTerm = "Alston"; const itemList = [ { categoryName: "Heating", plants: [ { plantId: 35, name: "Alston Oven", description: "Oven", plantCategoryId: 2, whenCreated: "1519357215942", }, { plantId: 19, name: "Gregs Oven", description: null, plantCategoryId: 2, whenCreated: "1516830724579", }, ], }, { categoryName: "Refrigeration", plants: [ { plantId: 13, name: "Fridge 1 ", description: "Walk in fridge" }, { plantId: 5, name: "Fridge 2 Updated", description: "Description of Fridge 2", }, { plantId: 4, name: "Fridge" }, ], }, ]; const output = itemList.filter((item) => { return item.plants.map((entry) => entry.name.toLowerCase()).join().includes(searchTerm.toLowerCase()); }); console.dir(output, { depth: null, color: true });

看

• Array.prototype.map()
• Array.prototype.filter()
• Array.prototype.join()

Answer 4

如果您只想過濾plants arrays，則不需要使用map 。 使用forEach() ，然后用過濾后的數組重新分配plants屬性。

this.itemList.forEach(item => 
    item.plants = item.plants.filter(p => 
        p.name.toLowerCase().includes(this.searchTerm.toLowerCase())));