表单在JavaScript对象中找到的属性名称数组

Question

我有以下对象

var columns = {ContributionType: "Employer Contribution",
               Employee1: "0",
               Employee2: "0",
               Employee3: "0"
              };

从这里我需要单独使用属性键来形成一个数组，如下面的

var keys=["ContributionType", "Employee1", "Employee2", "Employee3"];

属性数量是动态的

问题： 如何使用lodash或纯JavaScript实现此目的？

Answer 1

Object.keys()

var columns = {ContributionType: "Employer Contribution",
               Employee1: "0",
               Employee2: "0",
               Employee3: "0"
              };
var keys = Object.keys(columns);
console.log(keys);

Answer 2

var arr=[];
for (var key in columns)
{
//by using hasOwnProperty(key) we make sure that keys of
//the prototype are not included if any
if(columns.hasOwnProperty(key))
{
    arr.push(key);
}
}