javascript - 从对象中动态删除多个键/值对

Question

假设我有一个对象数组。有一些我不想要的键/值。删除一个键/值对的传统方法是这样使用delete:

for (var i = 0; i < tracks.length; i++) {
  delete tracks[i]["currency"];
  ...
}

我拉入的对象可能有 30 多对。有没有一种方法可以说明我想要哪些对并删除所有其他对？因此，例如，在这个对象数组中，我只想保留 trackName、kind、price

var tracks = [{
    trackNumber: "01",
    trackName: "Track 1",
    trackDuration: "5:35",
    kind: "song",
    currency: "USD",
    price: 1.29
}, {
    trackNumber: "02",
    trackName: "Track 2",
    trackDuration: "5:15",
    kind: "song",
    currency: "USD",
    price: 1.29
}, {
    trackNumber: "03",
    trackName: "Track 3",
    trackDuration: "5:07",
    kind: "song",
    currency: "USD",
    price: 1.29
}, {
    trackNumber: "04",
    trackName: "Track 4",
    trackDuration: "0:16",
    kind: "song",
    currency: "USD",
    price: 1.29
}, {
    trackNumber: "05",
    trackName: "Track 5",
    trackDuration: "5:35",
    kind: "song",
    currency: "USD",
    price: 1.29
}];

Answer 1

遍历数组并从每个对象中保留你想要的内容。

var keep = ['trackName', 'kind', 'price'];

for(var i = 0;i < tracks.length; i++){

    for(var key in tracks[i]){
        if(keep.indexOf(key) === -1)delete tracks[i][key];
    }

}