javascript - 将数组对象推送到新对象

我有以下数据：

var data = [{
    County: "Cork",
    date: '1/1/2018',
    num: 100
}, {
    County: "Roscommon",
    date: '07/10/2017',
    num: 27
}];
var Counties = {};
for (County in data) {
    for (var i = 0; i <= 1; i++) {
        Counties[data[i].County] = data[i].County;
    }
}

这将返回{County: "Roscommon"}

我如何获取代码以返回数组对象中的每个县，以便最终得到：

{County: "Cork"}
{County: "Roscommon"}

最佳答案

您可以使用array＃map函数。

const countyArray = data.map(el => {el.County})

要么

const counties = [];
for (let county of data) {
   counties.push({ County })
}

作为对象：

const counties = {};

for (let element of data) {
counties[element.County] = {County: element.County};
}