Cek Undefined, Null, dan Empty String di Javascript
- Categories:
- javascript
Dalam Javascript pengecekan terhadap suatu variabel apakah sudah dideklarasi (misal menggunakan var, let, atau const) dapat menggunakan operator typeof. Contoh:
if (typeof myVariable !== 'undefined') {
// your code
}Sedangkan untuk pengecekan suatu variabel yang telah dideklarasikan apakah bernilai undefined, null, atau blank / empty string dapat menggunakan:
if (myVariableToo) {
// your code
}Dalam kode diatas, myVariableToo akan bernilai true jika tidak:
nullundefinedNaN- blank atau empty string (‘’)
- 0
false
- Tags:
- #javascript
Recent Posts
How to Defend Against Brute-Force and DoS Attacks with Fail2ban, Nginx limit_req, and iptables
In this tutorial, I’ll explain how to protect your public-facing Linux server and Nginx web server from common threats, including brute-force and DoS attacks.
Is Getting AWS Solutions Architect Associate Certification Worth It?
If you are a full-time Software Engineer, there's no strong need to pursue this certification.
DevSecOps
My Notes about DevSecOps
AWS Secrets Manager
Explanation about AWS Secrets Manager with example code.
Envelope Encryption
Envelope encryption is the practice of encrypting plaintext data with a data key, and then encrypting the data key under another key.