Cara menggunakan javascript delete alternative

Question

I've been looking through a lot of blog posts, documentation, etc. about JavaScript's strict mode.

I noticed that there are a lot of restrictions on the delete keyword. I don't even know if you could call them restrictions. It seems like delete just no longer works.

I would love to use strict mode. It's a great idea. But I also think delete is a great idea.

Are there any alternative ways to "delete" a variable?

asked Apr 14, 2011 at 19:12

McKaylaMcKayla

6,7345 gold badges33 silver badges46 bronze badges

2

You do not delete variables.

delete is used to remove a property from an object.

delete foo.a will remove property "a" from object foo.

Why do you need to remove a local variable from scope? You can just set the variable to be undefined

(function(undefined) {
    // undefined is undefined.
})();

(function() {
    var undefined; // undefined is undefined
})();

Another way to check againts undefined would be doing foo === void 0 since void is an operator which runs the expression following it and returns undefined. It's a clever trick.

answered Apr 14, 2011 at 19:14

RaynosRaynos

163k56 gold badges347 silver badges394 bronze badges

26

How about just setting your variables to null? Once you set the variables to null, the JavaScript garbage collector will delete any unreferenced variables on next run.

HTH.

EDIT: As @chris Buckler mentioned in the comments, this can't be done at global scope, as global variables never get garbage collected.

answered Apr 14, 2011 at 19:17

Karl NicollKarl Nicoll

15.6k3 gold badges48 silver badges62 bronze badges

3

As others are alluding to, you should never really need to delete variables. It sounds more like an issue of not properly controlling scope. If you keep your variables in a function scope, they will be deallocated from memory once they are no longer referenced.

Do you have another global namespace other than the global window namespace? It would probably benefit you to have something like that for this situation:

(function(global) {

    var Application = {};

    Application.config = { /* config stuff */ };

    global.Application = Application;

})(window);

// if you need to remove config, you can remove it from
// your object and not the window object:
delete Application.config;

For a real in-depth understanding of deleting and undefined in JS:

http://perfectionkills.com/understanding-delete/

http://scottdowne.wordpress.com/2010/11/28/javascript-typeof-undefined-vs-undefined/

How do I check if an object has a property in JavaScript?

answered Apr 14, 2011 at 19:20

EliEli

16.8k4 gold badges35 silver badges49 bronze badges

4

Not the answer you're looking for? Browse other questions tagged javascript or ask your own question.

Cara menggunakan CSS-IN-JS pada JavaScript

Indonesian (Bahasa Indonesia) translation by Husain Ali Yahya (you can also view the original English article) Animasi merupakan salah satu fitur terbaik yang ada pada CSS untuk waktu yang lama. Pada ...

Cara menggunakan SYNTACT pada JavaScript

Sebelumnya, Anda telah melihat cara menggunakan fungsi output pada seri tutorial JavaScript ke- 11. Kali ini Codekey akan memberikan Anda tips penulisan syntax JavaScript. Seperti bahasa pemrograman ...

Cara menggunakan JQUERY.GETJSON pada JavaScript

Salam, bertemu kembali dalam tutorial jquery mempelajari belajar jquery, yang mudah-mudahan bermanfaat untuk Anda. Pada pertemuan sebelumnya kita telah mempelajari bagaimana menggunakan AJAX dengan ...

Cara menggunakan OGGETTI pada JavaScript

#Javascript #OOP Dalam kehidupan nyata, kita sering menjumpai objek. Objek adalah segala sesuatu yang ada di dunia ini.Entah itu benda mati ataupun makhluk hidup. Semuanya objek.Objek-objek ini dapat ...

Cara menggunakan EROOR pada JavaScript

Tutorial Belajar JavaScript Part 4: Cara Menampilkan Pesan Error JavaScript Sebelum mulai mengetik kode JavaScript, dalam tutorial kali ini kita akan bahas Cara Menampilkan Pesan Kesalahan (Error) ...

Cara menggunakan SET-LOCATION pada JavaScript

View DiscussionImprove ArticleSave ArticleReadDiscussView DiscussionImprove ArticleSave ArticleBoth location and location.href are used to set or return the complete URL of your current page. They ...

Cara menggunakan PARAMET pada JavaScript

Fungsi JavaScript tidak akan melakukan pemeriksaan apa pun pada nilai parameter (argumen).Section Artikel1 Parameter Fungsi dan Argumen2 Aturan Parameter3 Parameter Default4 Objek Argumen5 Argumen ...

Cara menggunakan JSCOLLECTIONS pada JavaScript

Content dated before 2011-04-08 (UTC) is licensed under CC BY-SA 2.5. Content dated from 2011-04-08 up to but not including 2018-05-02 (UTC) is licensed under CC BY-SA 3.0. Content dated on or after ...

Cara menggunakan TRY/CATCH pada JavaScript

Tidak peduli seberapa hebatnya kita dalam pemograman, terkadang kodingan kita memiliki banyak eror. Mereka mungkin muncul dikarenakan kesalahan kita, input dari user yang tidak terduga, eror respon ...

Cara menggunakan SWIRCH pada JavaScript

JavaScript - Javascript DasarBy 12 March 2016 JavaScript Javascript DasarBelajar Javascript Part 10 : Switch Case Di JavascriptBelajar Javascript Part 10 : Switch Case Di Javascript – Switch Case ...

Cara menggunakan SCHOOPS pada JavaScript

Loops can execute a block of code a number of times.JavaScript LoopsLoops are handy, if you want to run the same code over and over again, each time with a different value.Often this is the case when ...

Cara menggunakan FOLLWING pada JavaScript

Pemrograman fungsional telah membuat cukup banyak percikan di dunia pengembangan akhir-akhir ini. Dan untuk alasan yang baik: Teknik fungsional dapat membantumu menulis lebih banyak kode deklaratif ...

Cara menggunakan DOCUMEBT pada JavaScript

#Javascript Output adalah sebuah tampilan program yang biasanya digunakan untuk memperlihatkan hasil akhir.Output biasanya ditampilkan dalam bentuk teks dengan fungsi print().Ada 4 cara menampilkan ...

kode javascript