我正在寻求如何处理这个JSON的建议：
[{
"title":"Things",
"text":"1. Raindrops on roses 2. Whiskers on kittens 3. Bright copper kettles 4. Warm woolen mittens 5. Brown paper packages"
},{
"title":"Colors",
"text":"1. White 2. Blue 3. Red 4. Yellow 5. Green"
},{
"title":"Animals",
"text":"1. Dog 2. Rabbit 3. Cat 4. Squirrel 5. Duck"
},{
"title":"Colors",
"text":"1. Red 2. Blue 3. Orange 4. Green 5. Purple"
},{
"title":"Animals",
"text":"1. Bear 2. Bird 3. Duck 4. Squirrel 5. Rabbit"
},{
"title":"Colors",
"text":"1. Yellow 2. White 3. Black 4. Brown 5. Blue"
}]
返回这些可观察数组的集合：
为了解释，我需要做以下事情：
title对所有数组进行分组，计算其频率并返回新的List对象，例如Title: Colors, Count: 3 text项目以创建项目数组，计算其频率，根据索引位置为其分配一个分数（即[0] = 5到[4] = 1），求和得分并返回新的Item对象，例如Name: White, Score: 9, Count: 2 Lists和Count集合按Items，Score和Count对Name集合进行排序。我创建了以下javascript对象：
function List(title, items, count) {
var self = this;
self.Title = title;
self.Count = count;
self.Items = ko.observableArray(items);
}
function Item(name, count, score) {
var self = this;
self.Name = name;
self.Count = count;
self.Score = score;
}
我已经研究了我打算使用underscore.js攻击此任务的各种方法，但是由于报告在迭代数组中表现不佳而被推迟。
我预计JSON文件会比我展示的样本大得多，因此性能非常重要。
希望有些人可以提出实现目标的最佳方法，也许可以展示一个良好的起点。
提前致谢。
答案 0 :(得分：1)
我在此示例中使用Lo-Dash 2.2.1，但您可以轻松交换Underscore.js，因为它们的库_.each签名基本相同。
var collection = [{
"title":"Things",
"text":"1. Raindrops on roses 2. Whiskers on kittens 3. Bright copper kettles 4. Warm woolen mittens 5. Brown paper packages"
},{
"title":"Colors",
"text":"1. White 2. Blue 3. Red 4. Yellow 5. Green"
},{
"title":"Animals",
"text":"1. Dog 2. Rabbit 3. Cat 4. Squirrel 5. Duck"
},{
"title":"Colors",
"text":"1. Red 2. Blue 3. Orange 4. Green 5. Purple"
},{
"title":"Animals",
"text":"1. Bear 2. Bird 3. Duck 4. Squirrel 5. Rabbit"
},{
"title":"Colors",
"text":"1. Yellow 2. White 3. Black 4. Brown 5. Blue"
}];
//Store all the collections in a single place.
var collections = {};
_.each(collection, function(item){
//Does the collection exist?
if(!collections[item.title]){
//No? Add a new one
collections[item.title] = {Title:'', Items: {} };
}
//Split out the parts of the text by number period
var parts = item.text.split(/[0-9]+\./);
if(parts.length > 0){
parts.shift(); //remove the first entry in the array since it will be blank
}
//Iterate over each part text we found
_.each(parts, function(partName, i){
partName = partName.trim(); //remove whitespace
//Try to get an existing reference to the part
var part = collections[item.title].Items[partName];
//If the part doesn't exist
if(!part){
//Create a new one and add it to the collection
part = { Score: 0, Count: 0 };
collections[item.title].Items[partName] = part;
}
//Increment the score by the ordinal position
part.Score += i;
//Increment the count by 1
part.Count++;
});
});
//Store the final array of collections here
var finalData = [];
//Iterate over our current collection object
_.each(collections, function(collection, i){
var data = [];
//Convert the Items "hashtables"/objects into arrays
for(var key in collection.Items){
data.push({
'Name': key,
'Score': collection.Items[key].Score,
'Count': collection.Items[key].Count
});
}
collection.Items = data; //replace the Items object with the array
collection.Count = data.length; //compute the current count. (Although you could always call Items.length)
finalData.push(collection); //add the collection to the array.
});
console.log(finalData);
<强>结果
[
{
"Title": "Things",
"Items": [
{
"Name": "Raindrops on roses",
"Score": 0,
"Count": 1
},
{
"Name": "Whiskers on kittens",
"Score": 1,
"Count": 1
},
{
"Name": "Bright copper kettles",
"Score": 2,
"Count": 1
},
{
"Name": "Warm woolen mittens",
"Score": 3,
"Count": 1
},
{
"Name": "Brown paper packages",
"Score": 4,
"Count": 1
}
],
"Count": 5
},
{
"Title": "Colors",
"Items": [
{
"Name": "White",
"Score": 1,
"Count": 2
},
{
"Name": "Blue",
"Score": 6,
"Count": 3
},
{
"Name": "Red",
"Score": 2,
"Count": 2
},
{
"Name": "Yellow",
"Score": 3,
"Count": 2
},
{
"Name": "Green",
"Score": 7,
"Count": 2
},
{
"Name": "Orange",
"Score": 2,
"Count": 1
},
{
"Name": "Purple",
"Score": 4,
"Count": 1
},
{
"Name": "Black",
"Score": 2,
"Count": 1
},
{
"Name": "Brown",
"Score": 3,
"Count": 1
}
],
"Count": 9
},
{
"Title": "Animals",
"Items": [
{
"Name": "Dog",
"Score": 0,
"Count": 1
},
{
"Name": "Rabbit",
"Score": 5,
"Count": 2
},
{
"Name": "Cat",
"Score": 2,
"Count": 1
},
{
"Name": "Squirrel",
"Score": 6,
"Count": 2
},
{
"Name": "Duck",
"Score": 6,
"Count": 2
},
{
"Name": "Bear",
"Score": 0,
"Count": 1
},
{
"Name": "Bird",
"Score": 1,
"Count": 1
}
],
"Count": 7
}
]