javascript - 如何使用通配符从 JSON 对象中的任何属性获取最大值和最小值

Question

我需要从与此类似的 JSON 对象中获取以 Count 结尾的所有属性的最大值和最小值。我希望得到的最大值为 18，最小值为 3。

我能够获取单个属性的最大值 ( Getting max value(s) in JSON array )，但无法获取以 Count 结尾的任何内容。

[
{Period: 01/2017, Alpha: 5, AlphaCount: 10, Bravo: 3, BravoCount: 7, Charlie: 9, CharlieCount: 3}
{Period: 02/2017, Alpha: 2, AlphaCount: 4, Bravo: 3, BravoCount: 6, Charlie: 9, CharlieCount: 13}
{Period: 03/2017, Alpha: 6, AlphaCount: 8, Bravo: 3, BravoCount: 12, Charlie: 9, CharlieCount: 18}
]

Answer 1

您可以循环遍历整个数组并获取每个对象的键，使用indexOf()检查键中是否有“Count”，然后检查它是否为最大值。像这样的东西:

var arr = [
{Period: 01/2017, Alpha: 5, AlphaCount: 10, Bravo: 3, BravoCount: 7, Charlie: 9, CharlieCount: 3},
{Period: 02/2017, Alpha: 2, AlphaCount: 4, Bravo: 3, BravoCount: 6, Charlie: 9, CharlieCount: 13},
{Period: 03/2017, Alpha: 6, AlphaCount: 8, Bravo: 3, BravoCount: 12, Charlie: 9, CharlieCount: 18}
];
var max = -1;
arr.forEach(function(ob){
   var keys = Object.keys(ob);
   keys.forEach(x => max = x.indexOf('Count')>=0 && ob[x] >max ? ob[x]:max);
})
console.log(max);