我有一组具有相同属性的对象。每个对象都有大约一百个属性。我只想将其中的一小部分保留在新数组中：
var dummyArray = [{ "att1": "something", "att2": "something", ..., "att100": "something"}, { "att1": "something", "att2": "something", ..., "att100": "something"}, ...];
如何过滤/映射/减少...并提取有趣的键？
const newDummArray = dummyArray.map(function(item) {
delete item.att1;
delete item.att3;
delete item.att15;
// ... (long list)
return item;
});
我怎样才能只保留att20, att30, att70,att80为每个对象并删除其余的？
const dummyArray = [{ "att20": "att20", "att30": "att30", "att70": "att70", "att80": "att80"}, { "att20": "att20", "att30": "att30", "att70": "att70", "att80": "att80"}];
const result = dummyArray.map(({ att20, att30, att70, att80 }) => ({
att20,
att30,
att70,
att80
}));
console.log(result);map 创建一个新数组，所以不需要删除任何东西，而是创建一个有趣的键数组并返回它
var dummyArray = [{
"att1": "something",
"att2": "something",
"att20": "something",
"att100": "something"
}, {
"att1": "something",
"att2": "something",
"att20": "something",
"att100": "something"
}];
let x = dummyArray.map((item) => {
return {
attr20: item.att20
}
})
console.log(x)将您想要保留的props存储在一个数组中，然后为每个对象将想要的props转移到一个新对象。
var dummyArray = [{ "att1": "something", "att2": "something", "att100": "something"}, { "att1": "something", "att2": "something", "att100": "something"}];
var propsToKeep = ["att1", "att100"];
var result = dummyArray.map(item => {
const obj = {};
for (const prop of propsToKeep) {
obj[prop] = item[prop];
}
return obj;
})
console.log(result)这里有一个函数，它接受一个对象，并只提取你想要的属性。你通过一个数组作为第二个参数传递。
优点：更直接、更清洁。特别是当您只需要从一个对象中提取时。
如果你有一个对象列表。遍历列表并在每次迭代中提取。
function objectExtract(obj, properties) {
return properties.reduce((result, prop) => {
if (obj.hasOwnProperty(prop)) {
result[prop] = obj[prop];
}
return result;
}, {});
}
在此处阅读有关reduce 的信息https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce。
（redux 的真实例子）
store.dispatch(
setRooms({
...roomsState,
list: rooms.reduce((list, room) => {
list[room.id] = objectExtract(room, ['name', 'description', 'createdAt', 'updatedAt']);
return list;
}, {})
})
)
（以问题为例）
var dataSourceArray = [{
"att1": "something",
"att2": "something",
"att20": "something",
"att100": "something"
}, {
"att1": "something",
"att2": "something",
"att20": "something",
"att100": "something"
}];
let x = dataSourceArray.map((item) => {
return objectExtrac(item, ['att100', 'att2']);
});
我找到了最简单的方法来做这个 JSON.stringify()
JSON.stringify() 方法将 JavaScript 对象或值转换为 JSON 字符串，如果指定了替换器函数，则可以选择替换值，或者如果指定了替换器数组，则可以选择仅包含指定的属性。
const odata = [
{ "id": "0001", "type": "donut", "name": "Cake", "ppu": 0.55 },
{ "id": "0002", "type": "ansd", "name": "EARK", "ppu": 0.67 }
];
const outdata=JSON.stringify(odata,['id','type']);
console.log(outdata);