javascript - 如何从此嵌套对象数组中获取最大的 category_id？

Question

我是 reactjs 的初学者。我对循环嵌套对象数组以从该数组中找到最大的 category_Id 有疑问。我试过但我不知道如何在这里得到结果我们没有从最后一个索引数组中得到最大的 category_id 因为它可能在前面的索引数组中可用

0:
categories: Array(19)
0: {category_id: "2", name: "Cold Mezes", parent_id: "1", status: "1", products: Array(11), …}
1: {category_id: "3", name: "Hot Mezes", parent_id: "1", status: "1", products: Array(14), …}
2: {category_id: "5", name: "Wraps", parent_id: "1", status: "1", products: Array(4), …}
3: {category_id: "8", name: "Vegetarian Dishes", parent_id: "1", status: "1", products: Array(6), …}
4: {category_id: "9", name: "Authentic Dishes", parent_id: "1", status: "1", products: Array(5), …}
5: {category_id: "10", name: "Casseroles", parent_id: "1", status: "1", products: Array(3), …}
6: {category_id: "11", name: "Sharing Platter", parent_id: "1", status: "1", products: Array(2), …}
7: {category_id: "12", name: "Salads", parent_id: "1", status: "1", products: Array(4), …}
8: {category_id: "13", name: "Kids Menu", parent_id: "1", status: "1", products: Array(6), …}
9: {category_id: "14", name: "Side Dishes", parent_id: "1", status: "1", products: Array(5), …}
10: {category_id: "16", name: "Desserts", parent_id: "1", status: "1", products: Array(19), …}
11: {category_id: "6", name: "Yougurtlu Dishes", parent_id: "1", status: "1", products: Array(3), …}
12: {category_id: "7", name: "Fish Dishes", parent_id: "1", status: "1", products: Array(6), …}
13: {category_id: "4", name: "Main Course", parent_id: "1", status: "1", products: Array(17), …}
14: {category_id: "17", name: "Pasta", parent_id: "1", status: "1", products: Array(4), …}
15: {category_id: "18", name: "Turkish Breakfast", parent_id: "1", status: "1", products: Array(5), …}
16:
   categories: Array(11)
     0: {category_id: "20", name: "Cocktails", parent_id: "19", status: "1", products: Array(12), …}
     1: {category_id: "21", name: "Mocktails", parent_id: "19", status: "1", products: Array(5), …}
     2: {category_id: "22", name: "Beers", parent_id: "19", status: "1", products: Array(11), …}
     3: {category_id: "23", name: "Hot Drinks", parent_id: "19", status: "1", products: Array(13), …}
     4: {category_id: "24", name: "Soft Drinks", parent_id: "19", status: "1", products: Array(22), …}
     5: {category_id: "25", name: "White Wines", parent_id: "19", status: "1", products: Array(14), …}
     6: {category_id: "26", name: "Red Wines", parent_id: "19", status: "1", products: Array(13), …}
     7:
       categories: Array(7)
        0:
          categories: []
          category_id: "30"
          name: "Gin"
          parent_id: "27"
          products: (5) [{…}, {…}, {…}, {…}, {…}]
          status: "1"
          __proto__: Object
        1: {category_id: "31", name: "Rum", parent_id: "27", status: "1", products: Array(4), …}
        2: {category_id: "32", name: "Whisky", parent_id: "27", status: "1", products: Array(4), …}
        3: {category_id: "33", name: "Brandy", parent_id: "27", status: "1", products: Array(3), …}
        4: {category_id: "34", name: "Tequila", parent_id: "27", status: "1", products: Array(2), …}
        5: {category_id: "35", name: "Vodka", parent_id: "27", status: "1", products: Array(3), …}
        6: {category_id: "36", name: "Liqueurs", parent_id: "27", status: "1", products: Array(11), …}
           length: 7
        __proto__: Array(0)
       category_id: "27"
       name: "Spirits"
       parent_id: "19"
       products: []
       status: "1"
       __proto__: Object
   8: {category_id: "28", name: "Rose Wines", parent_id: "19", status: "1", products: Array(4), …}       
      length: 9
      __proto__: Array(0)
      category_id: "19"
      name: "Drinks"
      parent_id: "1"
      products: [{…}]
      status: "1"
      __proto__: Object

标签： javascriptarraysreactjsmultidimensional-arraynested-loops

Answer 1

使用recursive方法并比较id与max变量。

const categories = [
  { category_id: "1", categories: [] },
  {
    category_id: "2",
    categories: [
      {
        category_id: "10",
        categories: [{ category_id: "100", categories: [] }],
      },
    ],
  },
  { category_id: "3", categories: [] },
];

let max = -1;

const maxCat = (arr) => {
  arr.forEach(({ category_id, categories }) => {
    if (+category_id > max) {
      max = +category_id;
    }
    if (categories && categories.length > 0) {
      maxCat(categories);
    }
  });
};

maxCat(categories);
console.log(max);