What is Double exclamation mark in Javascript

 In JavaScript, the double exclamation operator converts an Object to Boolean. This happens such that “falsy” objects become false and “truthy” objects become true.

For example:

!! 0 –> false

!! null –> false

!! undefined –> false

!! 48 –> true

!! “hello” –> true

!! [1, 2, 3] –> true

This is a comprehensive guide on the double exclamation point operator.

references:

https://www.codingem.com/javascript-double-exclamation-operator/#:~:text=In%20JavaScript%2C%20the%20double%20exclamation,%E2%80%9Ctruthy%E2%80%9D%20objects%20become%20true.