Form of an array of property names found in a JavaScript object

Question

I have the following object

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

From this I need to form an array with these property keys separately, as after

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

Number of dynamic properties

Question: How can I achieve this using lodash or pure JavaScript?

Answer 1

Object.keys()

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

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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);
}
}