是否可以在此对象中合并？(javascript)

Question

有没有可能(如果可能的话)合并具有相同值的标签，这样一个标签就有了它所有图库的数组？

例如，从以下内容开始：

[{
    tag: "Kings",
    galleries: [
        "2016 Kings Draft Night"
    ]
}, {
    tag: "Draft",
    galleries: [
        "2016 Kings Draft Night"
    ]
}, {
    tag: "Kings",
    galleries: [
        "2016-17 Sacramento Kings Uniforms"
    ]
}]

并以此结束：

[{
    tag: "Kings",
    galleries: [
        "2016 Kings Draft Night", "2016-17 Sacramento Kings Uniforms"
    ]
}, {
    tag: "Draft",
    galleries: [
        "2016 Kings Draft Night"
    ]
}]

任何帮助都是非常感谢的。被这件事难住了

Answer 1

你可以filter() to concat() existing tag galleries，同时删除不必要的。

var result = data.filter(function(item) {
  var ref = this[item.tag];
  if(!ref) {
    return (this[item.tag] = item);
  }
  ref.galleries = ref.galleries.concat(item.galleries);
}, {});

​

var data = [{
  tag: "Kings",
  galleries: [
    "2016 Kings Draft Night"
  ]
}, {
  tag: "Draft",
  galleries: [
    "2016 Kings Draft Night"
  ]
}, {
  tag: "Kings",
  galleries: [
    "2016-17 Sacramento Kings Uniforms"
  ]
}];

var result = data.filter(function(item) {
  var ref = this[item.tag];
  if(!ref) {
    return (this[item.tag] = item);
  }
  ref.galleries = ref.galleries.concat(item.galleries);
}, {});

document.write('<pre>' + JSON.stringify(result, 0, 4) + '</pre>');

​

Answer 2

我相信有更快的方法可以做到这一点。但这是我想出来的：

​

var data = [{ tag: "Kings", galleries: [ "2016 Kings Draft Night" ] }, { tag: "Draft", galleries: [ "2016 Kings Draft Night" ] }, { tag: "Kings", galleries: [ "2016-17 Sacramento Kings Uniforms" ]}]


var newData = {};
data.forEach(function(a) {
  if (!newData[a.tag]) {
    newData[a.tag] = a.galleries;
  } else {
    newData[a.tag] = newData[a.tag].concat(a.galleries);
  }
});

var complete = [];
Object.keys(newData).forEach(function(key) {
  complete.push({
    tag: key,
    galleries: newData[key]
  });
});

console.log(complete);

​

Answer 3

合并功能：

function merge(a){
 var r = {},n = [];
 for(var d in a) 
  r[a[d].tag] = (r[a[d].tag]) ? r[a[d].tag].concat(a[d].galleries) : a[d].galleries;
 for(var d in r) n.push({'tag':d,'galleries':r[d]});
 return(n);
}

还有一个测试：

a = [{tag: "Kings",galleries: ["2016 Kings Draft Night"]},{tag: "Draft",galleries: ["2016 Kings Draft Night"]},{tag: "Kings",galleries: ["2016-17 Sacramento Kings Uniforms"]}];
console.log(merge(a));