循环遍历多个数组并保持每个元素的计数 [英] Loop through multiple array and keep count of each element

问题描述

我的 JSON 看起来像这样:

My JSON looks something like this:

[{
    "Name": "Test Post",
    "Id": 123,
    "ProductHandlingTypes": [{
         "Id": 1,
         "Name": "Type 1"
     },  
     {
         "Id": 2,
         "Name": "Type 2"
    }]
}, 
{
    "Name": "Test Post 2",
    "Id": 124,
    "ProductHandlingTypes": [{
        "Id": 3,
        "Name": "Type 3"
    },     
    {
        "Id": 1,
        "Name": "Type 1"
    }]
}]

所以，本质上，我希望能够遍历所有帖子的产品处理类型并将它们与产品处理类型列表进行比较，并且只要有匹配，我想跟踪有多少匹配/使用/找到特定类型的次数.

So, in essence, I would like to be able to loop through all of the post's product handling types and compare them to a list of product handling types and anytime there is a match, I would like to keep track of how many times that specific type has been matched/used/found.

我目前正在以这种方式检查匹配项，但我不确定如何对每种产品类型进行统计:

I am currently checking for matches this way, but I'm unsure of how to keep a tally of each product type:

postDataSource: new kendo.data.DataSource({
    transport: {
        read: { 
            url: "/path/to/get/posts",
            dataType: "json"
        }
    },
    schema: {
        parse: function (response) {
            // Get all product handling types
            viewModel.productHandlingTypesDataSource.fetch(function() {
                var types = this.data();
                // Loop through all of the posts
                for (var i = 0; i < response.length; i++) {
                    // Loop through each product handling type for each post
                    for (var j = 0; j < response[i].ProductHandlingTypes.length; j++) {
                        // Loop through every product handling type
                        for (var k = 0; k < types.length; k++) {
                            // Check if product handling type matches the post's product handling type(s)
                            if (response[i].ProductHandlingTypes[j].Name == types[k].Name) {
                                // Keep track of how many times this name matches
                            }
                        }
                    }
                }
            })

            return response;
        }
    }
})

我在试图用语言表达这个问题时遇到了一些麻烦，所以如果我需要澄清一些，请告诉我.

I've had some trouble trying to put this issue into words so if I need to clarify some more just let me know.

推荐答案

你可以像这样使用reduce:

var a = [{"Name":"TestPost","Id":123,"ProductHandlingTypes":[{"Id":1,"Name":"Type1"},{"Id":2,"Name":"Type2"}]},{"Name":"TestPost2","Id":124,"ProductHandlingTypes":[{"Id":3,"Name":"Type3"},{"Id":1,"Name":"Type1"}]}];

var b = a.reduce((acc, cur) => {
  cur.ProductHandlingTypes.map(({Name}) => Name).forEach(n => acc[n] = (acc[n] || 0) + 1);
  return acc;
}, {})

console.log(b)

它遍历您的数组并递增 Type n 值，或者在它们不存在时创建它们.

It loops through your array and increments Type n values or creates them is they don't exist.

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