JavaScript - 基于 3 个数组形成数组的函数（合并）

Question

给定以下 js 数组：var prices_A =[['company','100g','200g','300g'],['business_a','40€','50€',''],['business_b','50€','61€','42€'],['business_c','66€','','31€']]var prices_B =[['company','100g','200g','300g'],['business_b','40€','50€',''],['business_d','50€','61€','42€'],['business_e','66€','','31€']]var prices_C =[['company','100g','200g','300g'],['business_e','40€','50€',''],['business_b','66€','','31€']]如何使函数传递两个变量：grams 和 price_type，返回一个基于输入（传递的变量）合并数组的数组。price_type 可以是：prices_A、prices_B、prices_C 或prices_all。当prices_all 被引入时，它应该查询合并所有的价格（prices_A、prices_B 和prices_C）示例 1：var prices = myfunction(200,prices_C){}结果：prices =[['company','200g'],['business_e','50€']]示例 2：var prices = myfunction(100,prices_all){}结果：prices =[['company','100g_A','100g_B','100g_C'],['business_a','40€',''],['business_b','50€','40€','66€'],['business_c','66€',''],['business_d','','50€',''],['business_e','','66€','40€'],]

Answer 1

这是一个解决方案，它获取一个组的价格，如果给定或所有组，然后将这些组分配给单个数组。

function getPrices(weight, category) {

    function getByGroup(group) {

        var index = group[0].indexOf(weight);

        return group

            .map(a => [0, index].map(i => a[i]))

            .filter(a => a[1]);

    }

    return category in allPrices

        ? getByGroup(allPrices[category])

        : Object.entries(allPrices).reduce((r, [k, group], i) => {

            var temp = getByGroup(group),

                index;

            if (!temp.length) return r;

            temp[0][1] += '_' + k.slice(-1);

            if (!r) return temp;

            index = r[0].push(temp[0][1]) - 1;            

            temp.forEach(([company, price]) => {

                var row = r.find(([c]) => c === company);

                if (!row) {

                    r.push(row = [company]);

                } 

                row[index] = price;

            });

            r.forEach(a => a[index] = a[index] || '');

            return r;

        }, undefined);

}

var prices_A = [['company', '100g', '200g', '300g'], ['business_a', '40€', '50€', ''], ['business_b', '50€', '61€', '42€'], ['business_c', '66€', '', '31€']],

    prices_B = [['company', '100g', '200g', '300g'], ['business_b', '40€', '50€', ''], ['business_d', '50€', '61€', '42€'], ['business_e', '66€', '', '31€']],

    prices_C = [['company', '100g', '200g', '300g'], ['business_e', '40€', '50€', ''], ['business_b', '66€', '', '31€']],

    allPrices = { prices_A, prices_B, prices_C };

console.log(getPrices('200g', 'prices_C'));

console.log(getPrices('100g', 'prices_all'));

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