如何过滤 JavaScript 中的嵌套对象？

filter()方法创建一个新数组，其中包含所有通过所提供函数实现的测试的元素。

方法一：这种方法使用 filter() 方法来过滤 JavaScript 中的嵌套对象。

例子：

HTML

  

    Output
    
  
    
        var nestedObject = [
            {
                itemId: 1,
                itemDetails: {
                    name: "C",
                    caregory: "Programming Language",
                    price: 500,
                },
                itemCategory: "Basic",
            },
            {
                itemId: 2,
                itemDetails: {
                    name: "C++",
                    caregory: "Programming Language",
                    price: 700,
                },
                itemCategory: "Beginner",
            },
            {
                itemId: 1,
                itemDetails: {
                    name: "Java Script",
                    caregory: "Web Development",
                    price: 1500,
                },
                itemCategory: "Advanced",
            }]
        let itemNames = nestedObject.filter(
            eachObj => eachObj.itemDetails.price === 1500);
  
        document.getElementById("Output").innerHTML
            = JSON.stringify(itemNames);
    

  

输出：

在上面的例子中，只有“JavaScript”是价格为“1500”的课程名称。

方法 2：这种方法使用 some() 方法来过滤嵌套对象。 some()方法测试数组中是否至少有一个元素通过了提供的函数实现的测试。它返回一个布尔值。

例子：

HTML

  

    Output
    
  
    
        const fruitData = [
            {
                name: "Apples",
                details: [
                    {
                        fruitId: '1',
                        gradingDetails: [{ grade: 'A' }]
                    },
                    {
                        fruitId: '2',
                        gradingDetails: [{ grade: 'B' }]
                    }
                ]
            },
            {
                name: "Oranges",
                details: [
                    {
                        fruitId: '3',
                        gradingDetails: [{ grade: 'B' }]
                    },
                    {
                        fruitId: '4',
                        gradingDetails: [{ grade: 'D' }]
                    }
                ]
            },
        ];
  
        let output = fruitData.filter(eachVal => {
            let opt = eachVal.details.some((
                { gradingDetails }) => gradingDetails
                .some(({ grade }) => grade === 'A'));
            return opt;
        })
        console.log(output);
        document.getElementById("Output").innerHTML =
            JSON.stringify(output);
    

  

输出：

在上面的示例中，“Apples”的fruitId 为1，等级为“A”。但是对于 Oranges 来说，他们都不满足这个选择。