如何在下划线中将对象分组为一个对象

Question

如何转换：

[
  {name: 'foo', type: 'product'},
  {name: 'bar', type: 'product'},
  {name: 'john', type: 'product'},
  {name: 'no name', type: 'product'},
]

我如何分组并获取所有没有名称的对象：'no name' 作为单独的对象，如下所示：

{  
  0:[
    {name: 'foo', type: 'product'},
    {name: 'bar', type: 'product'},
    {name: 'john', type: 'product'}
  ],

  1:[
    {name: 'no name', type: 'product'},
  ]
}

Answer 1

要生成具有键 0 和 1 的对象，请使用 _.groupBy:

var objectResult = _.groupBy(data, function(d) { return +(d.name === "no name")  })

要生成一个包含两个元素的数组（也有键 0 和 1），您可以使用 _.partition（下划线 1.6.0 +）：

partition_.partition(array, predicate): Split array into two arrays: one whose elements all satisfy predicate and one whose elements all do not satisfy predicate.

var arrayResult = _.partition(data, function(d) { return d.name !== "no name"  })

JSBin

Answer 2

你可以试试http://underscorejs.org/#groupBy:

var data = [
  {name: 'foo', type: 'product'},
  {name: 'bar', type: 'product'},
  {name: 'john', type: 'product'},
  {name: 'no name', type: 'product'},
]

var results = _.groupBy(data, function(obj) { return obj.name == 'no name' ? 1 : 0; })

console.log(results)

Answer 3

你可以这样试试

var arr = [
 {name: 'foo', type: 'product'},
 {name: 'bar', type: 'product'},
 {name: 'john', type: 'product'},
 {name: 'no name', type: 'product'},
];

var result = _.groupBy(arr, function (elem) { 
 return elem.name == 'no name' ? 1: 0;
});

Answer 4

作为比较，纯 ECMAScript 只需要多一点代码：

data.reduce(function(acc, obj) {
  acc[obj.name == 'no name'? 1:0].push(obj);
  return acc;},{0:[],1:[]}
);

Answer 5

这么简单的东西为什么要用框架？这是一个允许正确分组的纯 JS 解决方案。然后很容易使用结果对象。

var array=[
  {name: 'foo', type: 'product'},
  {name: 'bar', type: 'product'},
  {name: 'john', type: 'product'},
  {name: 'no name', type: 'product'},
  {name: 'foo', type: 'product'},
  {name: 'bar', type: 'product'},
  {name: 'john', type: 'product'},
  {name: 'no name', type: 'product'},
  {name: 'no name', type: 'product'},
  {name: 'no name', type: 'product'},
  {name: 'no name', type: 'product'},
];        

function groupBy(propertyName, array) {
var groupedElements = {};
for (var i = 0, len = array.length; i < len; i++) {
    var el = array[i];
    var value = el[propertyName].trim();
    var group = groupedElements[value];
    if (group === undefined) {
        group = [el];
        groupedElements[value] = group;
    } else {
        group.push(el);
    }
}
return groupedElements;
}

var result = groupBy('name',array);

如何在下划线中将对象分组为一个对象

How to group objects into one object in underscore

javascript

arrays

underscore.js