Memory efficient way to make an object empty in javascript?

Question

Basically what I want to do is, to use single object everytime after make it empty when my purpose is served.
For array in javascript, I used to write arr.length=0 to make any array empty, instead of pointing it to different memory location. is there any way through which I can empty an object in javascript ?
Scenario is:

var obj = {};
obj["name"]="Aman";
obj["country"]="India";
console.log(obj); // output is { name: 'Aman', country: 'India' }

Can I reused this obj object after removing its content ? if so how ?

JSON is a data format. You are talking about "an object", there's nothing JSON about it. — Quentin
– Quentin, Commented Oct 17, 2013 at 7:07
@JoeSimmons — That wouldn't empty any other references to the same object. — Quentin
– Quentin, Commented Oct 17, 2013 at 7:08
@Quentin Yes I agree that JSON is a data format, but what my purpose is to make it empty. — Aman
– Aman, Commented Oct 17, 2013 at 7:09
You'll have to use a for..in loop to erase the properties. You should also use hasOwnProperty to make sure you only delete its own properties. — Joe Simmons
– Joe Simmons, Commented Oct 17, 2013 at 7:10
Remove the word JSON from your question and title. It has nothing to do with JavaScript objects. — Joe Simmons
– Joe Simmons, Commented Oct 17, 2013 at 7:11

Quentin · Accepted Answer · 2013-10-17 07:08:59Z

4

The only way I can think of would be to loop over the object and delete each property in turn.

var obj = {};
obj["name"]="Aman";
obj["country"]="India";

for (var prop in obj) {
    // Possibly with a hasOwnProperty test, depending on how empty you want it to be
    delete obj[prop];
}

console.log(obj);

Obviously, if you aren't dealing with multiple references to the object, you can just overwrite it with a new one.

var obj = {};
obj["name"]="Aman";
obj["country"]="India";

obj = {};

console.log(obj);

answered Oct 17, 2013 at 7:08

Quentin

949k136 gold badges1.3k silver badges1.4k bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Joe Simmons Over a year ago

Be sure to use hasOwnProperty -- don't want to be deleting any custom prototype methods.

Aman Over a year ago

appreciated... Thanks :)

mhchem Over a year ago

For how to do the first option in TypeScript, see stackoverflow.com/q/67323880/8772169

mhchem Over a year ago

Please note that the two ways differ in one important point if you use them on a parameter within a function. Way 1 will modify the object also outside the function, way 2 will not do that.

Joe Simmons · Accepted Answer · 2013-10-17 07:17:30Z

2

for (var member in myObject) {
    if ( myObject.hasOwnProperty(member) ) {
        delete myObject[member];
    }
}

edited Oct 17, 2013 at 7:17

Joe Simmons

1,8582 gold badges12 silver badges9 bronze badges

answered Oct 17, 2013 at 7:11

user2866717

1 Comment

Joe Simmons Over a year ago

Be sure to use hasOwnProperty -- don't want to be deleting any custom prototype methods.

4esn0k · Accepted Answer · 2013-10-17 07:47:59Z

0

use ECMAScript 6 Map:

var obj = new Map();
obj.set("name", "Aman");
obj.set("country", "India");
obj.clear();

answered Oct 17, 2013 at 7:47

4esn0k

10.6k7 gold badges38 silver badges40 bronze badges

2 Comments

Aman Over a year ago

I am not sure... but is it supported in all browsers ?

4esn0k Over a year ago

@Aman, not yet, but i hope somebody will investigate why Map was added to the spec

Collectives™ on Stack Overflow

Memory efficient way to make an object empty in javascript?

3 Answers 3

4 Comments

1 Comment

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

4 Comments

1 Comment

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related