not operator js

JavaScript
// || means orlet a = true;

let b = !a;

console.log(b); //output: falselet a = 1;
let b = -1;

if (a > 0 & b > 0){
	console.log("and");
} else if (a > 0 || b > 0){
	console.log("or");
} 
Source

Also in JavaScript: