最近开始使用javascript。我有一个扁平化的json,看起来像:
[
{"timestamp":"2019-01-01T00:00:00.000Z","MarketShare":89905.0,"Territory":"PHILADELPHIA PA"},
{"timestamp":"2019-01-01T00:00:00.000Z","MarketShare":82991.0,"Territory":"SEATTLE WA"},
{"timestamp":"2019-02-01T00:00:00.000Z","MarketShare":73662.0,"Territory":"PHILADELPHIA PA"},
{"timestamp":"2019-02-01T00:00:00.000Z","MarketShare":67059.0,"Territory":"SEATTLE WA"},
{"timestamp":"2019-03-01T00:00:00.000Z","MarketShare":72898.0,"Territory":"PHILADELPHIA PA"},
{"timestamp":"2019-03-01T00:00:00.000Z","MarketShare":68013.0,"Territory":"SEATTLE WA"},
{"timestamp":"2019-04-01T00:00:00.000Z","MarketShare":74607.0,"Territory":"PHILADELPHIA PA"},
{"timestamp":"2019-04-01T00:00:00.000Z","MarketShare":66769.0,"Territory":"SEATTLE WA"},
{"timestamp":"2019-05-01T00:00:00.000Z","MarketShare":93932.0,"Territory":"PHILADELPHIA PA"},
{"timestamp":"2019-05-01T00:00:00.000Z","MarketShare":86514.0,"Territory":"SEATTLE WA"}
]
基本上,对于给定的时间戳,我想在结果键下收集MarketShare和地区。
预期的输出是:
[
{
"timestamp":"2019-01-01T00:00:00.000Z",
"result":[
{
"MarketShare":89905.0,
"Territory":"PHILADELPHIA PA"
},
{
"MarketShare":82991.0,
"Territory":"SEATTLE WA"
},
]
},
{
"timestamp":"2019-02-01T00:00:00.000Z",
"result":[
{
"MarketShare":73662.0,
"Territory":"PHILADELPHIA PA"
},
{
"MarketShare":67059.0,
"Territory":"SEATTLE WA"
}
]
},
{
"timestamp":"2019-03-01T00:00:00.000Z",
"result":[
{
"MarketShare":72898.0,
"Territory":"PHILADELPHIA PA"
},
{
"MarketShare":68013.0,
"Territory":"SEATTLE WA"
}
]
},
{
"timestamp":"2019-04-01T00:00:00.000Z",
"result":[
{
"MarketShare":74607.0,
"Territory":"PHILADELPHIA PA"
},
{
"MarketShare":66769.0,
"Territory":"SEATTLE WA"
}
]
},
{
"timestamp":"2019-05-01T00:00:00.000Z",
"result":[
{
"MarketShare":93932.0,
"Territory":"PHILADELPHIA PA"
},
{
"MarketShare":86514.0,
"Territory":"SEATTLE WA"
}
]
}
]
我正在尝试创建一个通用实用程序,该实用程序将任意数量的键值对放在给定的时间戳下。到目前为止取得的进展:
topNFormat=[]
for(var i = 0; i < firstResult.length; i++) {
//res = [firstResult[i]["Territory"]
topNFormat[timestamp] = firstResult[i][timestamp] || {};
topNFormat[result] = firstResult[i][result] || [];
topNFormat[result].push(firstResult[i]);
//return collection;
}
答案 0 :(得分:2)
这是一个通用功能transform
,可以对项目进行动态分组:
const input = [{
"timestamp": "2019-01-01T00:00:00.000Z",
"MarketShare": 89905.0,
"Territory": "PHILADELPHIA PA"
},
{
"timestamp": "2019-01-01T00:00:00.000Z",
"MarketShare": 82991.0,
"Territory": "SEATTLE WA"
},
{
"timestamp": "2019-02-01T00:00:00.000Z",
"MarketShare": 73662.0,
"Territory": "PHILADELPHIA PA"
},
{
"timestamp": "2019-02-01T00:00:00.000Z",
"MarketShare": 67059.0,
"Territory": "SEATTLE WA"
},
{
"timestamp": "2019-03-01T00:00:00.000Z",
"MarketShare": 72898.0,
"Territory": "PHILADELPHIA PA"
},
{
"timestamp": "2019-03-01T00:00:00.000Z",
"MarketShare": 68013.0,
"Territory": "SEATTLE WA"
},
{
"timestamp": "2019-04-01T00:00:00.000Z",
"MarketShare": 74607.0,
"Territory": "PHILADELPHIA PA"
},
{
"timestamp": "2019-04-01T00:00:00.000Z",
"MarketShare": 66769.0,
"Territory": "SEATTLE WA"
},
{
"timestamp": "2019-05-01T00:00:00.000Z",
"MarketShare": 93932.0,
"Territory": "PHILADELPHIA PA"
},
{
"timestamp": "2019-05-01T00:00:00.000Z",
"MarketShare": 86514.0,
"Territory": "SEATTLE WA"
}
];
const transform = (array, groupBy, groupUnder) => array.reduce((acc, object) => {
if (groupBy in object) {
if (object[groupBy] in acc) {
acc[object[groupBy]][groupUnder] = [
...acc[object[groupBy]][groupUnder],
...[Object.keys(object).filter((key) => key !== groupBy).reduce((acc, key) => {
acc[key] = object[key];
return acc;
}, {})]
]
} else {
acc[object[groupBy]] = {
[groupUnder]: [Object.keys(object).filter((key) => key !== groupBy).reduce((acc, key) => {
acc[key] = object[key];
return acc;
}, {})]
}
}
}
return acc;
}, {});
const groupBy = 'timestamp';
const groupUnder = 'result';
const transformedResult = transform(input, groupBy, groupUnder);
console.log(transformedResult);
console.log('-'.repeat(100));
console.log(Object.keys(transformedResult).map((key) => Object.assign({}, transformedResult[key], {
[groupBy]: key
})));
答案 1 :(得分:1)
这是使用内置的reduce函数的简单解决方案:
[].reduce((memo, item) => {
memo[item.timestamp] = memo[item.timestamp] ||
{ timestamp: item.timestamp, result: [] };
memo[item.timestamp].result.push({
MarketShare: item.MarketShare,
Territory: item.Territory
});
return memo;
}, {});
更新2(更通用)
[].reduce((memo, item) => {
memo[item.timestamp] = memo[item.timestamp] ||
{ timestamp: item.timestamp, result: [] };
// push whole item into result list
memo[item.timestamp].result.push({ ...item });
return memo;
}, {});