Javascript 检查并动态推送新数组中的元素

Question

我有一个像下面数据这样的元素列表

[
    {
        "title": "First",
        "catalogCategories": [ "sport", "economy" ]
    },
    {
        "title": "Second",
        "catalogCategories": [ "politics", "tourism" ]
    },
    {
        "title": "Third",
        "catalogCategories": [ "sport", "universe" ]
    },
    {
        "title": "Fourth",
        "catalogCategories": [ "economy", "politics" ]
    }
]

我正在检查列表中的每个元素是否存在 catalogCategories 数组，如果存在，我只将任何元素的类别推入 catalogData 数组一次，因为碰巧任何元素的类别都可以相同，我在 catalogData 数组中过滤 catalogCategories

中元素的所有类别

这是下面的代码

  let categoryData = [];
  let isCategory = false

  for (let product of list) {
    if (product.catalogCategories[0].length > 0) {
      isCategory = true
      let isFound = false
      for (let i = 0; i < categoryData.length; i++) {
        if (categoryData[i].value === product.catalogCategories[0] || 
            categoryData[i].value === product.catalogCategories[1] ) {
          isFound = true;
        }
      }
      if (!isFound) {
        categoryData.push({"name": "catalogCategories", "label": product.catalogCategories[0], "selected": false, "value": product.catalogCategories[0]})
      }
    }

我的问题就在这里

  if (!isFound) {
    categoryData.push({"name": "catalogCategories", "label": product.catalogCategories[0], "selected": false, "value": product.catalogCategories[0]})
  }

如您所见，在所有这些检查之后，我总是只推送 catalogCategories 的第一个元素，我如何动态写下我可以推送第一个和/或第二个元素？

"value": product.catalogCategories[0]
"label": product.catalogCategories[0]

Answer 1

您需要首先使用 map 检查整个 catalogCategories 而不仅仅是第一个元素 product.catalogCategories[0] 并使用 new Map 来跟踪不重复的类别。

const list = [
    {
        "title": "First",
        "catalogCategories": [ "sport", "economy" ]
    },
    {
        "title": "Second",
        "catalogCategories": [ "politics", "tourism" ]
    },
    {
        "title": "Third",
        "catalogCategories": [ "sport", "universe" ]
    },
    {
        "title": "Fourth",
        "catalogCategories": [ "economy", "politics" ]
    }
]
let categoryDataMap = new Map();
for (let product of list) {
if (product.catalogCategories.length > 0) {
      product.catalogCategories.map(catalog=>{
        if(!categoryDataMap.has(catalog)){
            categoryDataMap.set(catalog,{"name": "catalogCategories", "label": catalog, "selected": false, "value": catalog})
        }
        })
    }
}
const categoryData = Array.from(categoryDataMap.values())
console.log(categoryData)

Javascript 检查并动态推送新数组中的元素

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