Form 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 they property keys alone like following

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

The number of properties is dynamic

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

score 1 · Accepted Answer · answered Jul 21 '15 at 14:59

1

Object.keys()

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

answered Jul 21 '15 at 14:59

epascarello

204,599
20
195
236

Untimely Answers · Answer 2 · 2015-07-21T20:39:27.540

1

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);
}
}

edited Jul 21 '15 at 20:39

answered Jul 21 '15 at 15:02

Untimely Answers

512
1
6
18

1

Be careful when using a loop like this. You may want to check `obj.hasOwnProperty(key)` to check that keys aren't being added by a prototype. – Phylogenesis Jul 21 '15 at 15:06
Thanks for pointing that out. – Untimely Answers Jul 21 '15 at 15:37

Form array of property names found in a JavaScript Object

2 Answers2

Linked