如何使用對象數據在angular2中創建多維數組？

Question

我有數組對象，但我想創建它的數組：對象格式如下：

[
 {"name":"A1","type":"type1"},
 {"name":"A2","type":"type1"},
 {"name":"A3","type":"type1"},
 {"name":"A4","type":"type1"},
 {"name":"B1","type":"type2"},
 {"name":"C1","type":"type3"},
 {"name":"D1","type":"type4"},
 {"name":"D2","type":"type4"}
]

結果格式如下：

["type1"=>[A1,A2,A3,A4],"type2"=>[B1],"type3"=>[C1],"type3"=>[D1,D2]]

Answer 1

您可以使用Array#forEach迭代數組，並使用類型為鍵的對象。

 var data = [{ "name": "A1", "type": "type1" }, { "name": "A2", "type": "type1" }, { "name": "A3", "type": "type1" }, { "name": "A4", "type": "type1" }, { "name": "B1", "type": "type2" }, { "name": "C1", "type": "type3" }, { "name": "D1", "type": "type4" }, { "name": "D2", "type": "type4" }], grouped = {}; data.forEach(function (a) { grouped[a.type] = grouped[a.type] || []; grouped[a.type].push(a.name); }); console.log(grouped); 

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Answer 2

您也可以減少

.reduce((prev, cur) => {
  if (prev.hasOwnProperty(cur.type))
    prev[cur.type].push(cur.name);
  else
    prev[cur.type] = [cur.name];

  return prev;
}, {});

這種方法的好處是，不需要在reduce范圍之外的其他變量，只需返回您的分組對象即可。

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