下划线js将对象数组的多个属性映射到新数组

Question

var items = [{
  //other properties... above
  item_name: [
    [1],
    [2, 3]
  ],
  item_description: [
    [1],
    [3, 4]
  ],
  item_quantity: [
    [1],
    [4, 5]
  ],
  item_value: null,
}, {
  //other properties... above
  item_name: 1,
  item_description: 2,
  item_quantity: 3,
  item_value: 4,
}, {
  //other properties... above
  item_name: [1, 2, 3],
  item_description: [1, 2, 3],
  item_quantity: [1, 2, 3],
  item_value: [1, 2, 3],
}];

var itemList = [];



items.forEach(function(item) {

  if (!_.isArray(item.item_name)) {
    itemList.push({
      name: item.item_name,
      description: item.item_description,
      quantity: item.item_quantity,
      value: item.item_value
    });
  }

  var names = item.item_name ? _.flatten(item.item_name) : [];
  var descriptions = item.item_description ? _.flatten(item.item_description) : [];
  var quantity = item.item_quantity ? _.flatten(item.item_quantity) : [];
  var values = item.item_value ? _.flatten(item.item_value) : [];

  names.forEach(function(name, index) {
    itemList.push({
      name: names[index],
      description: descriptions[index],
      quantity: quantity[index],
      values: values[index]
    });
  })
  

});
console.log(itemList);

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有没有一种方法可以在下划线中更快地执行此操作，以删除所有扁平化？

对于我正在使用的数组中的每一项

item_name[i]
item_description[i]
item_quantity[i]
item_value[i]

并将它们添加到 itemList

项目中的项目属性可以是 [[]、[]] 或 [] 或整数或 null

目前它正在输出预期的内容（除非名称为空并且它可以跳过项目）但是我不喜欢它正在执行的所有循环并且我想知道我是否可以更好地利用下划线库

Answer 1

你可以使用这个：

var myKeys = ['name', 'description', 'quantity', 'value'];
var result = _.flatten(items.map(function(item) {
    return _.zip.apply(_, myKeys.map(function(key) {
        return _.flatten([item['item_'+key]]);
    })).map(function(arr) {
        return _.object(myKeys, arr);
    });
}));

演示：

var items = [{
    //other properties... above
    item_name: [
        [1],
        [2, 3]
    ],
    item_description: [
        [1],
        [3, 4]
    ],
    item_quantity: [
        [1],
        [4, 5]
    ],
    item_value: null,
}, {
    //other properties... above
    item_name: 1,
    item_description: 2,
    item_quantity: 3,
    item_value: 4,
}, {
    //other properties... above
    item_name: [1, 2, 3],
    item_description: [1, 2, 3],
    item_quantity: [1, 2, 3],
    item_value: [1, 2, 3],
}];
var myKeys = ['name', 'description', 'quantity', 'value'];
var result = _.flatten(items.map(function(item) {
    return _.zip.apply(_, myKeys.map(function(key) {
        return _.flatten([item['item_'+key]]);
    })).map(function(arr) {
     return _.object(myKeys, arr);
    });
}));
console.log(result);

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下划线js将对象数组的多个属性映射到新数组

underscore js mapping array of objects multiple properties to new array

javascript

arrays

object

underscore.js